diff --git a/poky/bitbake/lib/bb/__init__.py b/poky/bitbake/lib/bb/__init__.py
index 7579a89..322a1e0 100644
--- a/poky/bitbake/lib/bb/__init__.py
+++ b/poky/bitbake/lib/bb/__init__.py
@@ -9,7 +9,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
-__version__ = "1.43.0"
+__version__ = "1.43.1"
 
 import sys
 if sys.version_info < (3, 4, 0):
diff --git a/poky/bitbake/lib/bb/build.py b/poky/bitbake/lib/bb/build.py
index e2f91fa..30a2ba2 100644
--- a/poky/bitbake/lib/bb/build.py
+++ b/poky/bitbake/lib/bb/build.py
@@ -54,23 +54,6 @@
 builtins['bb'] = bb
 builtins['os'] = os
 
-class FuncFailed(Exception):
-    def __init__(self, name = None, logfile = None):
-        self.logfile = logfile
-        self.name = name
-        if name:
-            self.msg = 'Function failed: %s' % name
-        else:
-            self.msg = "Function failed"
-
-    def __str__(self):
-        if self.logfile and os.path.exists(self.logfile):
-            msg = ("%s (log file is located at %s)" %
-                   (self.msg, self.logfile))
-        else:
-            msg = self.msg
-        return msg
-
 class TaskBase(event.Event):
     """Base class for task events"""
 
@@ -189,12 +172,7 @@
         return sys.stdout.name
 
 
-#
-# pythonexception allows the python exceptions generated to be raised
-# as the real exceptions (not FuncFailed) and without a backtrace at the
-# origin of the failure.
-#
-def exec_func(func, d, dirs = None, pythonexception=False):
+def exec_func(func, d, dirs = None):
     """Execute a BB 'function'"""
 
     try:
@@ -266,7 +244,7 @@
 
     with bb.utils.fileslocked(lockfiles):
         if ispython:
-            exec_func_python(func, d, runfile, cwd=adir, pythonexception=pythonexception)
+            exec_func_python(func, d, runfile, cwd=adir)
         else:
             exec_func_shell(func, d, runfile, cwd=adir)
 
@@ -286,7 +264,7 @@
 {function}(d)
 """
 logformatter = bb.msg.BBLogFormatter("%(levelname)s: %(message)s")
-def exec_func_python(func, d, runfile, cwd=None, pythonexception=False):
+def exec_func_python(func, d, runfile, cwd=None):
     """Execute a python BB 'function'"""
 
     code = _functionfmt.format(function=func)
@@ -311,14 +289,7 @@
         bb.methodpool.insert_method(func, text, fn, lineno - 1)
 
         comp = utils.better_compile(code, func, "exec_python_func() autogenerated")
-        utils.better_exec(comp, {"d": d}, code, "exec_python_func() autogenerated", pythonexception=pythonexception)
-    except (bb.parse.SkipRecipe, bb.build.FuncFailed):
-        raise
-    except Exception as e:
-        if pythonexception:
-            raise
-        logger.error(str(e))
-        raise FuncFailed(func, None)
+        utils.better_exec(comp, {"d": d}, code, "exec_python_func() autogenerated")
     finally:
         bb.debug(2, "Python function %s finished" % func)
 
@@ -475,13 +446,8 @@
     with open(fifopath, 'r+b', buffering=0) as fifo:
         try:
             bb.debug(2, "Executing shell function %s" % func)
-
-            try:
-                with open(os.devnull, 'r+') as stdin, logfile:
-                    bb.process.run(cmd, shell=False, stdin=stdin, log=logfile, extrafiles=[(fifo,readfifo)])
-            except bb.process.CmdError:
-                logfn = d.getVar('BB_LOGFILE')
-                raise FuncFailed(func, logfn)
+            with open(os.devnull, 'r+') as stdin, logfile:
+                bb.process.run(cmd, shell=False, stdin=stdin, log=logfile, extrafiles=[(fifo,readfifo)])
         finally:
             os.unlink(fifopath)
 
@@ -609,9 +575,6 @@
             event.fire(TaskStarted(task, logfn, flags, localdata), localdata)
         except (bb.BBHandledException, SystemExit):
             return 1
-        except FuncFailed as exc:
-            logger.error(str(exc))
-            return 1
 
         try:
             for func in (prefuncs or '').split():
@@ -619,7 +582,10 @@
             exec_func(task, localdata)
             for func in (postfuncs or '').split():
                 exec_func(func, localdata)
-        except FuncFailed as exc:
+        except bb.BBHandledException:
+            event.fire(TaskFailed(task, logfn, localdata, True), localdata)
+            return 1
+        except Exception as exc:
             if quieterr:
                 event.fire(TaskFailedSilent(task, logfn, localdata), localdata)
             else:
@@ -627,9 +593,6 @@
                 logger.error(str(exc))
                 event.fire(TaskFailed(task, logfn, localdata, errprinted), localdata)
             return 1
-        except bb.BBHandledException:
-            event.fire(TaskFailed(task, logfn, localdata, True), localdata)
-            return 1
     finally:
         sys.stdout.flush()
         sys.stderr.flush()
diff --git a/poky/bitbake/lib/bb/cache.py b/poky/bitbake/lib/bb/cache.py
index ab18dd5..b6f7da5 100644
--- a/poky/bitbake/lib/bb/cache.py
+++ b/poky/bitbake/lib/bb/cache.py
@@ -220,7 +220,7 @@
 
         cachedata.hashfn[fn] = self.hashfilename
         for task, taskhash in self.basetaskhashes.items():
-            identifier = '%s.%s' % (fn, task)
+            identifier = '%s:%s' % (fn, task)
             cachedata.basetaskhash[identifier] = taskhash
 
         cachedata.inherits[fn] = self.inherits
@@ -883,3 +883,56 @@
             p.dump([data, self.__class__.CACHE_VERSION])
 
         bb.utils.unlockfile(glf)
+
+
+class SimpleCache(object):
+    """
+    BitBake multi-process cache implementation
+
+    Used by the codeparser & file checksum caches
+    """
+
+    def __init__(self, version):
+        self.cachefile = None
+        self.cachedata = None
+        self.cacheversion = version
+
+    def init_cache(self, d, cache_file_name=None, defaultdata=None):
+        cachedir = (d.getVar("PERSISTENT_DIR") or
+                    d.getVar("CACHE"))
+        if not cachedir:
+            return defaultdata
+
+        bb.utils.mkdirhier(cachedir)
+        self.cachefile = os.path.join(cachedir,
+                                      cache_file_name or self.__class__.cache_file_name)
+        logger.debug(1, "Using cache in '%s'", self.cachefile)
+
+        glf = bb.utils.lockfile(self.cachefile + ".lock")
+
+        try:
+            with open(self.cachefile, "rb") as f:
+                p = pickle.Unpickler(f)
+                data, version = p.load()
+        except:
+            bb.utils.unlockfile(glf)
+            return defaultdata
+
+        bb.utils.unlockfile(glf)
+
+        if version != self.cacheversion:
+            return defaultdata
+
+        return data
+
+    def save(self, data):
+        if not self.cachefile:
+            return
+
+        glf = bb.utils.lockfile(self.cachefile + ".lock")
+
+        with open(self.cachefile, "wb") as f:
+            p = pickle.Pickler(f, -1)
+            p.dump([data, self.cacheversion])
+
+        bb.utils.unlockfile(glf)
diff --git a/poky/bitbake/lib/bb/cooker.py b/poky/bitbake/lib/bb/cooker.py
index b4851e1..0607fcc 100644
--- a/poky/bitbake/lib/bb/cooker.py
+++ b/poky/bitbake/lib/bb/cooker.py
@@ -31,6 +31,7 @@
 import json
 import pickle
 import codecs
+import hashserv
 
 logger      = logging.getLogger("BitBake")
 collectlog  = logging.getLogger("BitBake.Collection")
@@ -192,6 +193,8 @@
         bb.parse.BBHandler.cached_statements = {}
 
         self.ui_cmdline = None
+        self.hashserv = None
+        self.hashservport = None
 
         self.initConfigurationData()
 
@@ -372,8 +375,6 @@
         # Copy of the data store which has been expanded.
         # Used for firing events and accessing variables where expansion needs to be accounted for
         #
-        bb.parse.init_parser(self.data)
-
         if CookerFeatures.BASEDATASTORE_TRACKING in self.featureset:
             self.disableDataTracking()
 
@@ -391,6 +392,22 @@
         except prserv.serv.PRServiceConfigError as e:
             bb.fatal("Unable to start PR Server, exitting")
 
+        if self.data.getVar("BB_HASHSERVE") == "localhost:0":
+            if not self.hashserv:
+                dbfile = (self.data.getVar("PERSISTENT_DIR") or self.data.getVar("CACHE")) + "/hashserv.db"
+                self.hashserv = hashserv.create_server(('localhost', 0), dbfile, '')
+                self.hashservport = "localhost:" + str(self.hashserv.server_port)
+                self.hashserv.process = multiprocessing.Process(target=self.hashserv.serve_forever)
+                self.hashserv.process.daemon = True
+                self.hashserv.process.start()
+            self.data.setVar("BB_HASHSERVE", self.hashservport)
+            self.databuilder.origdata.setVar("BB_HASHSERVE", self.hashservport)
+            self.databuilder.data.setVar("BB_HASHSERVE", self.hashservport)
+            for mc in self.databuilder.mcdata:
+                self.databuilder.mcdata[mc].setVar("BB_HASHSERVE", self.hashservport)
+
+        bb.parse.init_parser(self.data)
+
     def enableDataTracking(self):
         self.configuration.tracking = True
         if hasattr(self, "data"):
@@ -1645,9 +1662,11 @@
 
     def post_serve(self):
         prserv.serv.auto_shutdown()
+        if self.hashserv:
+            self.hashserv.process.terminate()
+            self.hashserv.process.join()
         bb.event.fire(CookerExit(), self.data)
 
-
     def shutdown(self, force = False):
         if force:
             self.state = state.forceshutdown
@@ -1662,6 +1681,7 @@
 
     def reset(self):
         self.initConfigurationData()
+        self.handlePRServ()
 
     def clientComplete(self):
         """Called when the client is done using the server"""
@@ -2062,6 +2082,14 @@
             for process in self.processes:
                 self.parser_quit.put(None)
 
+        # Cleanup the queue before call process.join(), otherwise there might be
+        # deadlocks.
+        while True:
+            try:
+               self.result_queue.get(timeout=0.25)
+            except queue.Empty:
+                break
+
         for process in self.processes:
             if force:
                 process.join(.1)
diff --git a/poky/bitbake/lib/bb/data.py b/poky/bitbake/lib/bb/data.py
index 92ef405..0d75d0c 100644
--- a/poky/bitbake/lib/bb/data.py
+++ b/poky/bitbake/lib/bb/data.py
@@ -130,7 +130,7 @@
         if all:
             oval = d.getVar(var, False)
         val = d.getVar(var)
-    except (KeyboardInterrupt, bb.build.FuncFailed):
+    except (KeyboardInterrupt):
         raise
     except Exception as exc:
         o.write('# expansion of %s threw %s: %s\n' % (var, exc.__class__.__name__, str(exc)))
@@ -422,7 +422,7 @@
             var = lookupcache[dep]
             if var is not None:
                 data = data + str(var)
-        k = fn + "." + task
+        k = fn + ":" + task
         basehash[k] = hashlib.sha256(data.encode("utf-8")).hexdigest()
         taskdeps[task] = alldeps
 
diff --git a/poky/bitbake/lib/bb/fetch2/npm.py b/poky/bitbake/lib/bb/fetch2/npm.py
index 4427b1b..9700e61 100644
--- a/poky/bitbake/lib/bb/fetch2/npm.py
+++ b/poky/bitbake/lib/bb/fetch2/npm.py
@@ -101,11 +101,19 @@
             return False
         return True
 
-    def _runwget(self, ud, d, command, quiet):
-        logger.debug(2, "Fetching %s using command '%s'" % (ud.url, command))
-        bb.fetch2.check_network_access(d, command, ud.url)
+    def _runpack(self, ud, d, pkgfullname: str, quiet=False) -> str:
+        """
+        Runs npm pack on a full package name.
+        Returns the filename of the downloaded package
+        """
+        bb.fetch2.check_network_access(d, pkgfullname, ud.registry)
         dldir = d.getVar("DL_DIR")
-        runfetchcmd(command, d, quiet, workdir=dldir)
+        dldir = os.path.join(dldir, ud.prefixdir)
+
+        command = "npm pack {} --registry {}".format(pkgfullname, ud.registry)
+        logger.debug(2, "Fetching {} using command '{}' in {}".format(pkgfullname, command, dldir))
+        filename = runfetchcmd(command, d, quiet, workdir=dldir)
+        return filename.rstrip()
 
     def _unpackdep(self, ud, pkg, data, destdir, dldir, d):
         file = data[pkg]['tgz']
@@ -163,6 +171,9 @@
         pkgfullname = pkg
         if version != '*' and not '/' in version:
             pkgfullname += "@'%s'" % version
+        if pkgfullname in fetchedlist:
+            return
+
         logger.debug(2, "Calling getdeps on %s" % pkg)
         fetchcmd = "npm view %s --json --registry %s" % (pkgfullname, ud.registry)
         output = runfetchcmd(fetchcmd, d, True)
@@ -182,15 +193,10 @@
                 if (not blacklist and 'linux' not in pkg_os) or '!linux' in pkg_os:
                     logger.debug(2, "Skipping %s since it's incompatible with Linux" % pkg)
                     return
-        #logger.debug(2, "Output URL is %s - %s - %s" % (ud.basepath, ud.basename, ud.localfile))
-        outputurl = pdata['dist']['tarball']
+        filename = self._runpack(ud, d, pkgfullname)
         data[pkg] = {}
-        data[pkg]['tgz'] = os.path.basename(outputurl)
-        if outputurl in fetchedlist:
-            return
-
-        self._runwget(ud, d, "%s --directory-prefix=%s %s" % (self.basecmd, ud.prefixdir, outputurl), False)
-        fetchedlist.append(outputurl)
+        data[pkg]['tgz'] = filename
+        fetchedlist.append(pkgfullname)
 
         dependencies = pdata.get('dependencies', {})
         optionalDependencies = pdata.get('optionalDependencies', {})
@@ -217,17 +223,12 @@
                     if obj == pkg:
                         self._getshrinkeddependencies(obj, data['dependencies'][obj], data['dependencies'][obj]['version'], d, ud, lockdown, manifest, False)
                         return
-        outputurl = "invalid"
-        if ('resolved' not in data) or (not data['resolved'].startswith('http://') and not data['resolved'].startswith('https://')):
-            # will be the case for ${PN}
-            fetchcmd = "npm view %s@%s dist.tarball --registry %s" % (pkg, version, ud.registry)
-            logger.debug(2, "Found this matching URL: %s" % str(fetchcmd))
-            outputurl = runfetchcmd(fetchcmd, d, True)
-        else:
-            outputurl = data['resolved']
-        self._runwget(ud, d, "%s --directory-prefix=%s %s" % (self.basecmd, ud.prefixdir, outputurl), False)
+
+        pkgnameWithVersion = "{}@{}".format(pkg, version)
+        logger.debug(2, "Get dependencies for {}".format(pkgnameWithVersion))
+        filename = self._runpack(ud, d, pkgnameWithVersion)
         manifest[pkg] = {}
-        manifest[pkg]['tgz'] = os.path.basename(outputurl).rstrip()
+        manifest[pkg]['tgz'] = filename
         manifest[pkg]['deps'] = {}
 
         if pkg in lockdown:
diff --git a/poky/bitbake/lib/bb/fetch2/wget.py b/poky/bitbake/lib/bb/fetch2/wget.py
index 0f71ee4..725586d 100644
--- a/poky/bitbake/lib/bb/fetch2/wget.py
+++ b/poky/bitbake/lib/bb/fetch2/wget.py
@@ -257,13 +257,15 @@
                 fp.read()
                 fp.close()
 
-                newheaders = dict((k, v) for k, v in list(req.headers.items())
-                                  if k.lower() not in ("content-length", "content-type"))
-                return self.parent.open(urllib.request.Request(req.get_full_url(),
-                                                        headers=newheaders,
-                                                        origin_req_host=req.origin_req_host,
-                                                        unverifiable=True))
+                if req.get_method() != 'GET':
+                    newheaders = dict((k, v) for k, v in list(req.headers.items())
+                                      if k.lower() not in ("content-length", "content-type"))
+                    return self.parent.open(urllib.request.Request(req.get_full_url(),
+                                                            headers=newheaders,
+                                                            origin_req_host=req.origin_req_host,
+                                                            unverifiable=True))
 
+                raise urllib.request.HTTPError(req, code, msg, headers, None)
 
             # Some servers (e.g. GitHub archives, hosted on Amazon S3) return 403
             # Forbidden when they actually mean 405 Method Not Allowed.
diff --git a/poky/bitbake/lib/bb/runqueue.py b/poky/bitbake/lib/bb/runqueue.py
index 6a2de24..7fa074f 100644
--- a/poky/bitbake/lib/bb/runqueue.py
+++ b/poky/bitbake/lib/bb/runqueue.py
@@ -133,7 +133,7 @@
 
         self.prio_map = [self.rqdata.runtaskentries.keys()]
 
-        self.buildable = []
+        self.buildable = set()
         self.skip_maxthread = {}
         self.stamps = {}
         for tid in self.rqdata.runtaskentries:
@@ -148,8 +148,10 @@
         """
         Return the id of the first task we find that is buildable
         """
-        self.buildable = [x for x in self.buildable if x not in self.rq.runq_running]
-        buildable = [x for x in self.buildable if (x in self.rq.tasks_covered or x in self.rq.tasks_notcovered)]
+        buildable = set(self.buildable)
+        buildable.difference_update(self.rq.runq_running)
+        buildable.difference_update(self.rq.holdoff_tasks)
+        buildable.intersection_update(self.rq.tasks_covered | self.rq.tasks_notcovered)
         if not buildable:
             return None
 
@@ -167,7 +169,7 @@
                 skip_buildable[rtaskname] = 1
 
         if len(buildable) == 1:
-            tid = buildable[0]
+            tid = buildable.pop()
             taskname = taskname_from_tid(tid)
             if taskname in skip_buildable and skip_buildable[taskname] >= int(self.skip_maxthread[taskname]):
                 return None
@@ -204,7 +206,10 @@
             return self.next_buildable_task()
 
     def newbuildable(self, task):
-        self.buildable.append(task)
+        self.buildable.add(task)
+
+    def removebuildable(self, task):
+        self.buildable.remove(task)
 
     def describe_task(self, taskid):
         result = 'ID %s' % taskid
@@ -1171,10 +1176,9 @@
     def prepare_task_hash(self, tid):
         procdep = []
         for dep in self.runtaskentries[tid].depends:
-            procdep.append(fn_from_tid(dep) + "." + taskname_from_tid(dep))
-        (mc, fn, taskname, taskfn) = split_tid_mcfn(tid)
-        self.runtaskentries[tid].hash = bb.parse.siggen.get_taskhash(taskfn, taskname, procdep, self.dataCaches[mc])
-        self.runtaskentries[tid].unihash = bb.parse.siggen.get_unihash(taskfn + "." + taskname)
+            procdep.append(dep)
+        self.runtaskentries[tid].hash = bb.parse.siggen.get_taskhash(tid, procdep, self.dataCaches[mc_from_tid(tid)])
+        self.runtaskentries[tid].unihash = bb.parse.siggen.get_unihash(tid)
 
     def dump_data(self):
         """
@@ -1251,6 +1255,7 @@
             "buildname" : self.cfgData.getVar("BUILDNAME"),
             "date" : self.cfgData.getVar("DATE"),
             "time" : self.cfgData.getVar("TIME"),
+            "hashservport" : self.cooker.hashservport,
         }
 
         worker.stdin.write(b"<cookerconfig>" + pickle.dumps(self.cooker.configuration) + b"</cookerconfig>")
@@ -1384,57 +1389,29 @@
             cache[tid] = iscurrent
         return iscurrent
 
-    def validate_hashes(self, tocheck, data, presentcount=None, siginfo=False):
+    def validate_hashes(self, tocheck, data, currentcount=None, siginfo=False):
         valid = set()
         if self.hashvalidate:
-            sq_hash = []
-            sq_hashfn = []
-            sq_unihash = []
-            sq_fn = []
-            sq_taskname = []
-            sq_task = []
+            sq_data = {}
+            sq_data['hash'] = {}
+            sq_data['hashfn'] = {}
+            sq_data['unihash'] = {}
             for tid in tocheck:
                 (mc, fn, taskname, taskfn) = split_tid_mcfn(tid)
+                sq_data['hash'][tid] = self.rqdata.runtaskentries[tid].hash
+                sq_data['hashfn'][tid] = self.rqdata.dataCaches[mc].hashfn[taskfn]
+                sq_data['unihash'][tid] = self.rqdata.runtaskentries[tid].unihash
 
-                sq_fn.append(fn)
-                sq_hashfn.append(self.rqdata.dataCaches[mc].hashfn[taskfn])
-                sq_hash.append(self.rqdata.runtaskentries[tid].hash)
-                sq_unihash.append(self.rqdata.runtaskentries[tid].unihash)
-                sq_taskname.append(taskname)
-                sq_task.append(tid)
-
-            if presentcount is not None:
-                data.setVar("BB_SETSCENE_STAMPCURRENT_COUNT", presentcount)
-
-            valid_ids = self.validate_hash(sq_fn, sq_taskname, sq_hash, sq_hashfn, siginfo, sq_unihash, data, presentcount)
-
-            if presentcount is not None:
-                data.delVar("BB_SETSCENE_STAMPCURRENT_COUNT")
-
-            for v in valid_ids:
-                valid.add(sq_task[v])
+            valid = self.validate_hash(sq_data, data, siginfo, currentcount)
 
         return valid
 
-    def validate_hash(self, sq_fn, sq_task, sq_hash, sq_hashfn, siginfo, sq_unihash, d, presentcount):
-        locs = {"sq_fn" : sq_fn, "sq_task" : sq_task, "sq_hash" : sq_hash, "sq_hashfn" : sq_hashfn,
-                "sq_unihash" : sq_unihash, "siginfo" : siginfo, "d" : d}
+    def validate_hash(self, sq_data, d, siginfo, currentcount):
+        locs = {"sq_data" : sq_data, "d" : d, "siginfo" : siginfo, "currentcount" : currentcount}
 
-        # Backwards compatibility
-        hashvalidate_args = ("(sq_fn, sq_task, sq_hash, sq_hashfn, d, siginfo=siginfo, sq_unihash=sq_unihash)",
-                             "(sq_fn, sq_task, sq_hash, sq_hashfn, d, siginfo=siginfo)",
-                             "(sq_fn, sq_task, sq_hash, sq_hashfn, d)")
+        # Metadata has **kwargs so args can be added, sq_data can also gain new fields
+        call = self.hashvalidate + "(sq_data, d, siginfo=siginfo, currentcount=currentcount)"
 
-        for args in hashvalidate_args[:-1]:
-            try:
-                call = self.hashvalidate + args
-                return bb.utils.better_eval(call, locs)
-            except TypeError:
-                continue
-
-        # Call the last entry without a try...catch to propagate any thrown
-        # TypeError
-        call = self.hashvalidate + hashvalidate_args[-1]
         return bb.utils.better_eval(call, locs)
 
     def _execute_runqueue(self):
@@ -1516,6 +1493,7 @@
             self.dm_event_handler_registered = False
 
         if build_done and self.rqexe:
+            bb.parse.siggen.save_unitaskhashes()
             self.teardown_workers()
             if self.rqexe:
                 if self.rqexe.stats.failed:
@@ -1718,6 +1696,9 @@
         self.sq_running = set()
         self.sq_live = set()
 
+        self.updated_taskhash_queue = []
+        self.pending_migrations = set()
+
         self.runq_buildable = set()
         self.runq_running = set()
         self.runq_complete = set()
@@ -1729,6 +1710,7 @@
 
         self.stampcache = {}
 
+        self.holdoff_tasks = set()
         self.sqdone = False
 
         self.stats = RunQueueStats(len(self.rqdata.runtaskentries))
@@ -1751,7 +1733,10 @@
         self.tasks_notcovered = set()
         self.scenequeue_notneeded = set()
 
-        self.coveredtopocess = set()
+        # We can't skip specified target tasks which aren't setscene tasks
+        self.cantskip = set(self.rqdata.target_tids)
+        self.cantskip.difference_update(self.rqdata.runq_setscene_tids)
+        self.cantskip.intersection_update(self.rqdata.runtaskentries)
 
         schedulers = self.get_schedulers()
         for scheduler in schedulers:
@@ -1763,9 +1748,9 @@
             bb.fatal("Invalid scheduler '%s'.  Available schedulers: %s" %
                      (self.scheduler, ", ".join(obj.name for obj in schedulers)))
 
-        if len(self.rqdata.runq_setscene_tids) > 0:
-            self.sqdata = SQData()
-            build_scenequeue_data(self.sqdata, self.rqdata, self.rq, self.cooker, self.stampcache, self)
+        #if len(self.rqdata.runq_setscene_tids) > 0:
+        self.sqdata = SQData()
+        build_scenequeue_data(self.sqdata, self.rqdata, self.rq, self.cooker, self.stampcache, self)
 
     def runqueue_process_waitpid(self, task, status):
 
@@ -1831,6 +1816,9 @@
         if not self.rq.depvalidate:
             return False
 
+        # Must not edit parent data
+        taskdeps = set(taskdeps)
+
         taskdata = {}
         taskdeps.add(task)
         for dep in taskdeps:
@@ -1918,17 +1906,58 @@
         self.stats.taskSkipped()
         self.stats.taskCompleted()
 
+    def summarise_scenequeue_errors(self):
+        err = False
+        if not self.sqdone:
+            logger.debug(1, 'We could skip tasks %s', "\n".join(sorted(self.scenequeue_covered)))
+            completeevent = sceneQueueComplete(self.sq_stats, self.rq)
+            bb.event.fire(completeevent, self.cfgData)
+        if self.sq_deferred:
+            logger.error("Scenequeue had deferred entries: %s" % pprint.pformat(self.sq_deferred))
+            err = True
+        if self.updated_taskhash_queue:
+            logger.error("Scenequeue had unprocessed changed taskhash entries: %s" % pprint.pformat(self.updated_taskhash_queue))
+            err = True
+        if self.holdoff_tasks:
+            logger.error("Scenequeue had holdoff tasks: %s" % pprint.pformat(self.holdoff_tasks))
+            err = True
+
+        for tid in self.rqdata.runq_setscene_tids:
+            if tid not in self.scenequeue_covered and tid not in self.scenequeue_notcovered:
+                err = True
+                logger.error("Setscene Task %s was never marked as covered or not covered" % tid)
+            if tid not in self.sq_buildable:
+                err = True
+                logger.error("Setscene Task %s was never marked as buildable" % tid)
+            if tid not in self.sq_running:
+                err = True
+                logger.error("Setscene Task %s was never marked as running" % tid)
+
+        for x in self.rqdata.runtaskentries:
+            if x not in self.tasks_covered and x not in self.tasks_notcovered:
+                logger.error("Task %s was never moved from the setscene queue" % x)
+                err = True
+            if x not in self.tasks_scenequeue_done:
+                logger.error("Task %s was never processed by the setscene code" % x)
+                err = True
+            if len(self.rqdata.runtaskentries[x].depends) == 0 and x not in self.runq_buildable:
+                logger.error("Task %s was never marked as buildable by the setscene code" % x)
+                err = True
+        return err
+
+
     def execute(self):
         """
         Run the tasks in a queue prepared by prepare_runqueue
         """
 
         self.rq.read_workers()
+        self.process_possible_migrations()
 
         task = None
         if not self.sqdone and self.can_start_task():
             # Find the next setscene to run
-            for nexttask in self.rqdata.runq_setscene_tids:
+            for nexttask in sorted(self.rqdata.runq_setscene_tids):
                 if nexttask in self.sq_buildable and nexttask not in self.sq_running and self.sqdata.stamps[nexttask] not in self.build_stamps.values():
                     if nexttask not in self.sqdata.unskippable and len(self.sqdata.sq_revdeps[nexttask]) > 0 and self.sqdata.sq_revdeps[nexttask].issubset(self.scenequeue_covered) and self.check_dependencies(nexttask, self.sqdata.sq_revdeps[nexttask]):
                         if nexttask not in self.rqdata.target_tids:
@@ -1938,6 +1967,10 @@
                             if nexttask in self.sq_deferred:
                                 del self.sq_deferred[nexttask]
                             return True
+                    # If covered tasks are running, need to wait for them to complete
+                    for t in self.sqdata.sq_covered_tasks[nexttask]:
+                        if t in self.runq_running and t not in self.runq_complete:
+                            continue
                     if nexttask in self.sq_deferred:
                         if self.sq_deferred[nexttask] not in self.runq_complete:
                             continue
@@ -2006,24 +2039,10 @@
             if self.can_start_task():
                 return True
 
-        if not self.sq_live and not self.sqdone and not self.sq_deferred:
+        if not self.sq_live and not self.sqdone and not self.sq_deferred and not self.updated_taskhash_queue and not self.holdoff_tasks:
             logger.info("Setscene tasks completed")
-            logger.debug(1, 'We could skip tasks %s', "\n".join(sorted(self.scenequeue_covered)))
 
-            completeevent = sceneQueueComplete(self.sq_stats, self.rq)
-            bb.event.fire(completeevent, self.cfgData)
-
-            err = False
-            for x in self.rqdata.runtaskentries:
-                if x not in self.tasks_covered and x not in self.tasks_notcovered:
-                    logger.error("Task %s was never moved from the setscene queue" % x)
-                    err = True
-                if x not in self.tasks_scenequeue_done:
-                    logger.error("Task %s was never processed by the setscene code" % x)
-                    err = True
-                if len(self.rqdata.runtaskentries[x].depends) == 0 and x not in self.runq_buildable:
-                    logger.error("Task %s was never marked as buildable by the setscene code" % x)
-                    err = True
+            err = self.summarise_scenequeue_errors()
             if err:
                 self.rq.state = runQueueFailed
                 return True
@@ -2119,14 +2138,22 @@
             return True
 
         # Sanity Checks
+        err = self.summarise_scenequeue_errors()
         for task in self.rqdata.runtaskentries:
             if task not in self.runq_buildable:
                 logger.error("Task %s never buildable!", task)
+                err = True
             elif task not in self.runq_running:
                 logger.error("Task %s never ran!", task)
+                err = True
             elif task not in self.runq_complete:
                 logger.error("Task %s never completed!", task)
-        self.rq.state = runQueueComplete
+                err = True
+
+        if err:
+            self.rq.state = runQueueFailed
+        else:
+            self.rq.state = runQueueComplete
 
         return True
 
@@ -2144,7 +2171,7 @@
     # as most code can't handle them
     def build_taskdepdata(self, task):
         taskdepdata = {}
-        next = self.rqdata.runtaskentries[task].depends
+        next = self.rqdata.runtaskentries[task].depends.copy()
         next.add(task)
         next = self.filtermcdeps(task, next)
         while next:
@@ -2166,57 +2193,153 @@
         #bb.note("Task %s: " % task + str(taskdepdata).replace("], ", "],\n"))
         return taskdepdata
 
-    def scenequeue_process_notcovered(self, task):
-        if len(self.rqdata.runtaskentries[task].depends) == 0:
-            self.setbuildable(task)
-        notcovered = set([task])
-        while notcovered:
-            new = set()
-            for t in notcovered:
-                for deptask in self.rqdata.runtaskentries[t].depends:
-                    if deptask in notcovered or deptask in new or deptask in self.rqdata.runq_setscene_tids or deptask in self.tasks_notcovered:
-                        continue
-                    logger.debug(1, 'Task %s depends on non-setscene task %s so not skipping' % (t, deptask))
-                    new.add(deptask)
-                    self.tasks_notcovered.add(deptask)
-                    if len(self.rqdata.runtaskentries[deptask].depends) == 0:
-                        self.setbuildable(deptask)
-            notcovered = new
+    def update_holdofftasks(self):
+        self.holdoff_tasks = set()
 
-    def scenequeue_process_unskippable(self, task):
-        # Look up the dependency chain for non-setscene things which depend on this task
-        # and mark as 'done'/notcovered
-        ready = set([task])
-        while ready:
-            new = set()
-            for t in ready:
-                for deptask in self.rqdata.runtaskentries[t].revdeps:
-                    if deptask in ready or deptask in new or deptask in self.tasks_scenequeue_done or deptask in self.rqdata.runq_setscene_tids:
-                        continue
-                    if self.rqdata.runtaskentries[deptask].depends.issubset(self.tasks_scenequeue_done):
-                        new.add(deptask)
-                        self.tasks_scenequeue_done.add(deptask)
-                        self.tasks_notcovered.add(deptask)
-                        #logger.warning("Up: " + str(deptask))
-            ready = new
+        for tid in self.rqdata.runq_setscene_tids:
+            if tid not in self.scenequeue_covered and tid not in self.scenequeue_notcovered:
+                self.holdoff_tasks.add(tid)
+
+        for tid in self.holdoff_tasks.copy():
+            for dep in self.sqdata.sq_covered_tasks[tid]:
+                if dep not in self.runq_complete:
+                    self.holdoff_tasks.add(dep)
+
+    def process_possible_migrations(self):
+
+        changed = set()
+        for tid, unihash in self.updated_taskhash_queue.copy():
+            if tid in self.runq_running and tid not in self.runq_complete:
+                continue
+
+            self.updated_taskhash_queue.remove((tid, unihash))
+
+            if unihash != self.rqdata.runtaskentries[tid].unihash:
+                logger.info("Task %s unihash changed to %s" % (tid, unihash))
+                self.rqdata.runtaskentries[tid].unihash = unihash
+                bb.parse.siggen.set_unihash(tid, unihash)
+
+                # Work out all tasks which depend on this one
+                total = set()
+                next = set(self.rqdata.runtaskentries[tid].revdeps)
+                while next:
+                    current = next.copy()
+                    total = total |next
+                    next = set()
+                    for ntid in current:
+                        next |= self.rqdata.runtaskentries[ntid].revdeps
+                        next.difference_update(total)
+
+                # Now iterate those tasks in dependency order to regenerate their taskhash/unihash
+                done = set()
+                next = set(self.rqdata.runtaskentries[tid].revdeps)
+                while next:
+                    current = next.copy()
+                    next = set()
+                    for tid in current:
+                        if not self.rqdata.runtaskentries[tid].depends.isdisjoint(total):
+                            continue
+                        procdep = []
+                        for dep in self.rqdata.runtaskentries[tid].depends:
+                            procdep.append(dep)
+                        orighash = self.rqdata.runtaskentries[tid].hash
+                        self.rqdata.runtaskentries[tid].hash = bb.parse.siggen.get_taskhash(tid, procdep, self.rqdata.dataCaches[mc_from_tid(tid)])
+                        origuni = self.rqdata.runtaskentries[tid].unihash
+                        self.rqdata.runtaskentries[tid].unihash = bb.parse.siggen.get_unihash(tid)
+                        logger.debug(1, "Task %s hash changes: %s->%s %s->%s" % (tid, orighash, self.rqdata.runtaskentries[tid].hash, origuni, self.rqdata.runtaskentries[tid].unihash))
+                        next |= self.rqdata.runtaskentries[tid].revdeps
+                        changed.add(tid)
+                        total.remove(tid)
+                        next.intersection_update(total)
+
+        if changed:
+            for mc in self.rq.worker:
+                self.rq.worker[mc].process.stdin.write(b"<newtaskhashes>" + pickle.dumps(bb.parse.siggen.get_taskhashes()) + b"</newtaskhashes>")
+            for mc in self.rq.fakeworker:
+                self.rq.fakeworker[mc].process.stdin.write(b"<newtaskhashes>" + pickle.dumps(bb.parse.siggen.get_taskhashes()) + b"</newtaskhashes>")
+
+            logger.debug(1, pprint.pformat("Tasks changed:\n%s" % (changed)))
+
+        for tid in changed:
+            if tid not in self.rqdata.runq_setscene_tids:
+                continue
+            valid = self.rq.validate_hashes(set([tid]), self.cooker.data, None, False)
+            if not valid:
+                continue
+            if tid in self.runq_running:
+                continue
+            if tid not in self.pending_migrations:
+                self.pending_migrations.add(tid)
+
+        for tid in self.pending_migrations.copy():
+            valid = True
+            # Check no tasks this covers are running
+            for dep in self.sqdata.sq_covered_tasks[tid]:
+                if dep in self.runq_running and dep not in self.runq_complete:
+                    logger.debug(2, "Task %s is running which blocks setscene for %s from running" % (dep, tid))
+                    valid = False
+                    break
+            if not valid:
+                continue
+
+            self.pending_migrations.remove(tid)
+
+            if tid in self.tasks_scenequeue_done:
+                self.tasks_scenequeue_done.remove(tid)
+            for dep in self.sqdata.sq_covered_tasks[tid]:
+                if dep not in self.runq_complete:
+                    if dep in self.tasks_scenequeue_done and dep not in self.sqdata.unskippable:
+                        self.tasks_scenequeue_done.remove(dep)
+
+            if tid in self.sq_buildable:
+                self.sq_buildable.remove(tid)
+            if tid in self.sq_running:
+                self.sq_running.remove(tid)
+            if self.sqdata.sq_revdeps[tid].issubset(self.scenequeue_covered | self.scenequeue_notcovered):
+                if tid not in self.sq_buildable:
+                    self.sq_buildable.add(tid)
+            if len(self.sqdata.sq_revdeps[tid]) == 0:
+                self.sq_buildable.add(tid)
+
+            if tid in self.sqdata.outrightfail:
+                self.sqdata.outrightfail.remove(tid)
+            if tid in self.scenequeue_notcovered:
+                self.scenequeue_notcovered.remove(tid)
+            if tid in self.scenequeue_covered:
+                self.scenequeue_covered.remove(tid)
+            if tid in self.scenequeue_notneeded:
+                self.scenequeue_notneeded.remove(tid)
+
+            (mc, fn, taskname, taskfn) = split_tid_mcfn(tid)
+            self.sqdata.stamps[tid] = bb.build.stampfile(taskname + "_setscene", self.rqdata.dataCaches[mc], taskfn, noextra=True)
+
+            if tid in self.stampcache:
+                del self.stampcache[tid]
+
+            if tid in self.build_stamps:
+                del self.build_stamps[tid]
+
+            logger.info("Setscene task %s now valid and being rerun" % tid)
+            self.sqdone = False
+
+        if changed:
+            self.update_holdofftasks()
 
     def scenequeue_updatecounters(self, task, fail=False):
-        for dep in self.sqdata.sq_deps[task]:
+
+        for dep in sorted(self.sqdata.sq_deps[task]):
             if fail and task in self.sqdata.sq_harddeps and dep in self.sqdata.sq_harddeps[task]:
                 logger.debug(2, "%s was unavailable and is a hard dependency of %s so skipping" % (task, dep))
                 self.sq_task_failoutright(dep)
                 continue
-            if task not in self.sqdata.sq_revdeps2[dep]:
-                # May already have been removed by the fail case above
-                continue
-            self.sqdata.sq_revdeps2[dep].remove(task)
-            if len(self.sqdata.sq_revdeps2[dep]) == 0:
-                self.sq_buildable.add(dep)
+            if self.sqdata.sq_revdeps[dep].issubset(self.scenequeue_covered | self.scenequeue_notcovered):
+                if dep not in self.sq_buildable:
+                    self.sq_buildable.add(dep)
 
         next = set([task])
         while next:
             new = set()
-            for t in next:
+            for t in sorted(next):
                 self.tasks_scenequeue_done.add(t)
                 # Look down the dependency chain for non-setscene things which this task depends on
                 # and mark as 'done'
@@ -2225,39 +2348,31 @@
                         continue
                     if self.rqdata.runtaskentries[dep].revdeps.issubset(self.tasks_scenequeue_done):
                         new.add(dep)
-                        #logger.warning(" Down: " + dep)
             next = new
 
-        if task in self.sqdata.unskippable:
-            self.scenequeue_process_unskippable(task)
+        notcovered = set(self.scenequeue_notcovered)
+        notcovered |= self.cantskip
+        for tid in self.scenequeue_notcovered:
+            notcovered |= self.sqdata.sq_covered_tasks[tid]
+        notcovered |= self.sqdata.unskippable.difference(self.rqdata.runq_setscene_tids)
+        notcovered.intersection_update(self.tasks_scenequeue_done)
 
-        if task in self.scenequeue_notcovered:
-            logger.debug(1, 'Not skipping setscene task %s', task)
-            self.scenequeue_process_notcovered(task)
-        elif task in self.scenequeue_covered:
-            logger.debug(1, 'Queued setscene task %s', task)
-            self.coveredtopocess.add(task)
+        covered = set(self.scenequeue_covered)
+        for tid in self.scenequeue_covered:
+            covered |= self.sqdata.sq_covered_tasks[tid]
+        covered.difference_update(notcovered)
+        covered.intersection_update(self.tasks_scenequeue_done)
 
-        for task in self.coveredtopocess.copy():
-            if self.sqdata.sq_covered_tasks[task].issubset(self.tasks_scenequeue_done):
-                logger.debug(1, 'Processing setscene task %s', task)
-                covered = self.sqdata.sq_covered_tasks[task]
-                covered.add(task)
+        for tid in notcovered | covered:
+            if len(self.rqdata.runtaskentries[tid].depends) == 0:
+                self.setbuildable(tid)
+            elif self.rqdata.runtaskentries[tid].depends.issubset(self.runq_complete):
+                 self.setbuildable(tid)
 
-                # If a task is in target_tids and isn't a setscene task, we can't skip it.
-                cantskip = covered.intersection(self.rqdata.target_tids).difference(self.rqdata.runq_setscene_tids)
-                for tid in cantskip:
-                    self.tasks_notcovered.add(tid)
-                    self.scenequeue_process_notcovered(tid)
-                covered.difference_update(cantskip)
+        self.tasks_covered = covered
+        self.tasks_notcovered = notcovered
 
-                # Remove notcovered tasks
-                covered.difference_update(self.tasks_notcovered)
-                self.tasks_covered.update(covered)
-                self.coveredtopocess.remove(task)
-                for tid in covered:
-                    if len(self.rqdata.runtaskentries[tid].depends) == 0:
-                        self.setbuildable(tid)
+        self.update_holdofftasks()
 
     def sq_task_completeoutright(self, task):
         """
@@ -2268,7 +2383,6 @@
 
         logger.debug(1, 'Found task %s which could be accelerated', task)
         self.scenequeue_covered.add(task)
-        self.tasks_covered.add(task)
         self.scenequeue_updatecounters(task)
 
     def sq_check_taskfail(self, task):
@@ -2289,7 +2403,6 @@
         self.sq_stats.taskFailed()
         bb.event.fire(sceneQueueTaskFailed(task, self.sq_stats, result, self), self.cfgData)
         self.scenequeue_notcovered.add(task)
-        self.tasks_notcovered.add(task)
         self.scenequeue_updatecounters(task, True)
         self.sq_check_taskfail(task)
 
@@ -2299,7 +2412,6 @@
         self.sq_stats.taskSkipped()
         self.sq_stats.taskCompleted()
         self.scenequeue_notcovered.add(task)
-        self.tasks_notcovered.add(task)
         self.scenequeue_updatecounters(task, True)
 
     def sq_task_skip(self, task):
@@ -2377,8 +2489,6 @@
         self.sq_deps = {}
         # SceneQueue reverse dependencies
         self.sq_revdeps = {}
-        # Copy of reverse dependencies used by sq processing code
-        self.sq_revdeps2 = {}
         # Injected inter-setscene task dependencies
         self.sq_harddeps = {}
         # Cache of stamp files so duplicates can't run in parallel
@@ -2458,27 +2568,28 @@
 
     rqdata.init_progress_reporter.next_stage()
 
-    # Build a list of setscene tasks which are "unskippable"
-    # These are direct endpoints referenced by the build
+    # Build a list of tasks which are "unskippable"
+    # These are direct endpoints referenced by the build upto and including setscene tasks
     # Take the build endpoints (no revdeps) and find the sstate tasks they depend upon
     new = True
     for tid in rqdata.runtaskentries:
         if len(rqdata.runtaskentries[tid].revdeps) == 0:
             sqdata.unskippable.add(tid)
+    sqdata.unskippable |= sqrq.cantskip
     while new:
         new = False
-        for tid in sqdata.unskippable.copy():
+        orig = sqdata.unskippable.copy()
+        for tid in sorted(orig, reverse=True):
             if tid in rqdata.runq_setscene_tids:
                 continue
-            sqdata.unskippable.remove(tid)
             if len(rqdata.runtaskentries[tid].depends) == 0:
                 # These are tasks which have no setscene tasks in their chain, need to mark as directly buildable
-                sqrq.tasks_notcovered.add(tid)
-                sqrq.tasks_scenequeue_done.add(tid)
                 sqrq.setbuildable(tid)
-                sqrq.scenequeue_process_unskippable(tid)
             sqdata.unskippable |= rqdata.runtaskentries[tid].depends
-            new = True
+            if sqdata.unskippable != orig:
+                new = True
+
+    sqrq.tasks_scenequeue_done |= sqdata.unskippable.difference(rqdata.runq_setscene_tids)
 
     rqdata.init_progress_reporter.next_stage(len(rqdata.runtaskentries))
 
@@ -2537,7 +2648,6 @@
     #    bb.warn("Task %s_setscene: is %s " % (tid, data))
 
     sqdata.sq_revdeps = sq_revdeps_squash
-    sqdata.sq_revdeps2 = copy.deepcopy(sqdata.sq_revdeps)
     sqdata.sq_covered_tasks = sq_collated_deps
 
     # Build reverse version of revdeps to populate deps structure
@@ -2562,7 +2672,7 @@
         stamppresent = []
         tocheck = set()
 
-        for tid in sqdata.sq_revdeps:
+        for tid in sorted(sqdata.sq_revdeps):
             (mc, fn, taskname, taskfn) = split_tid_mcfn(tid)
 
             taskdep = rqdata.dataCaches[mc].task_deps[taskfn]
@@ -2595,7 +2705,7 @@
 
         hashes = {}
         for mc in sorted(multiconfigs):
-          for tid in sqdata.sq_revdeps:
+          for tid in sorted(sqdata.sq_revdeps):
             if mc_from_tid(tid) != mc:
                 continue
             if tid not in valid_new and tid not in noexec and tid not in sqrq.scenequeue_notcovered:
@@ -2715,6 +2825,15 @@
         runQueueEvent.__init__(self, task, stats, rq)
         self.reason = reason
 
+class taskUniHashUpdate(bb.event.Event):
+    """
+    Base runQueue event class
+    """
+    def __init__(self, task, unihash):
+        self.taskid = task
+        self.unihash = unihash
+        bb.event.Event.__init__(self)
+
 class runQueuePipe():
     """
     Abstraction for a pipe between a worker thread and the server
@@ -2757,6 +2876,8 @@
                 except ValueError as e:
                     bb.msg.fatal("RunQueue", "failed load pickle '%s': '%s'" % (e, self.queue[7:index]))
                 bb.event.fire_from_worker(event, self.d)
+                if isinstance(event, taskUniHashUpdate):
+                    self.rqexec.updated_taskhash_queue.append((event.taskid, event.unihash))
                 found = True
                 self.queue = self.queue[index+8:]
                 index = self.queue.find(b"</event>")
diff --git a/poky/bitbake/lib/bb/server/process.py b/poky/bitbake/lib/bb/server/process.py
index f901fe5..69aae62 100644
--- a/poky/bitbake/lib/bb/server/process.py
+++ b/poky/bitbake/lib/bb/server/process.py
@@ -456,7 +456,10 @@
         self.configuration.setServerRegIdleCallback(server.register_idle_function)
         os.close(self.readypipe)
         writer = ConnectionWriter(self.readypipein)
-        self.cooker = bb.cooker.BBCooker(self.configuration, self.featureset)
+        try:
+            self.cooker = bb.cooker.BBCooker(self.configuration, self.featureset)
+        except bb.BBHandledException:
+            return None
         writer.send("r")
         writer.close()
         server.cooker = self.cooker
diff --git a/poky/bitbake/lib/bb/siggen.py b/poky/bitbake/lib/bb/siggen.py
index 6a729f3..b503559 100644
--- a/poky/bitbake/lib/bb/siggen.py
+++ b/poky/bitbake/lib/bb/siggen.py
@@ -12,6 +12,7 @@
 import difflib
 import simplediff
 from bb.checksum import FileChecksumCache
+from bb import runqueue
 
 logger = logging.getLogger('BitBake.SigGen')
 
@@ -41,17 +42,17 @@
         self.runtaskdeps = {}
         self.file_checksum_values = {}
         self.taints = {}
+        self.unitaskhashes = {}
 
     def finalise(self, fn, d, varient):
         return
 
-    def get_unihash(self, task):
-        return self.taskhash[task]
+    def get_unihash(self, tid):
+        return self.taskhash[tid]
 
-    def get_taskhash(self, fn, task, deps, dataCache):
-        k = fn + "." + task
-        self.taskhash[k] = hashlib.sha256(k.encode("utf-8")).hexdigest()
-        return self.taskhash[k]
+    def get_taskhash(self, tid, deps, dataCache):
+        self.taskhash[tid] = hashlib.sha256(tid.encode("utf-8")).hexdigest()
+        return self.taskhash[tid]
 
     def writeout_file_checksum_cache(self):
         """Write/update the file checksum cache onto disk"""
@@ -73,14 +74,23 @@
         return
 
     def get_taskdata(self):
-        return (self.runtaskdeps, self.taskhash, self.file_checksum_values, self.taints, self.basehash)
+        return (self.runtaskdeps, self.taskhash, self.file_checksum_values, self.taints, self.basehash, self.unitaskhashes)
 
     def set_taskdata(self, data):
-        self.runtaskdeps, self.taskhash, self.file_checksum_values, self.taints, self.basehash = data
+        self.runtaskdeps, self.taskhash, self.file_checksum_values, self.taints, self.basehash, self.unitaskhashes = data
 
     def reset(self, data):
         self.__init__(data)
 
+    def get_taskhashes(self):
+        return self.taskhash, self.unitaskhashes
+
+    def set_taskhashes(self, hashes):
+        self.taskhash, self.unitaskhashes = hashes
+
+    def save_unitaskhashes(self):
+        return
+
 
 class SignatureGeneratorBasic(SignatureGenerator):
     """
@@ -96,7 +106,6 @@
         self.taints = {}
         self.gendeps = {}
         self.lookupcache = {}
-        self.pkgnameextract = re.compile(r"(?P<fn>.*)\..*")
         self.basewhitelist = set((data.getVar("BB_HASHBASE_WHITELIST") or "").split())
         self.taskwhitelist = None
         self.init_rundepcheck(data)
@@ -107,6 +116,9 @@
         else:
             self.checksum_cache = None
 
+        self.unihash_cache = bb.cache.SimpleCache("1")
+        self.unitaskhashes = self.unihash_cache.init_cache(data, "bb_unihashes.dat", {})
+
     def init_rundepcheck(self, data):
         self.taskwhitelist = data.getVar("BB_HASHTASK_WHITELIST") or None
         if self.taskwhitelist:
@@ -122,16 +134,16 @@
         taskdeps, basehash = bb.data.generate_dependency_hash(tasklist, gendeps, lookupcache, self.basewhitelist, fn)
 
         for task in tasklist:
-            k = fn + "." + task
-            if not ignore_mismatch and k in self.basehash and self.basehash[k] != basehash[k]:
-                bb.error("When reparsing %s, the basehash value changed from %s to %s. The metadata is not deterministic and this needs to be fixed." % (k, self.basehash[k], basehash[k]))
+            tid = fn + ":" + task
+            if not ignore_mismatch and tid in self.basehash and self.basehash[tid] != basehash[tid]:
+                bb.error("When reparsing %s, the basehash value changed from %s to %s. The metadata is not deterministic and this needs to be fixed." % (tid, self.basehash[tid], basehash[tid]))
                 bb.error("The following commands may help:")
                 cmd = "$ bitbake %s -c%s" % (d.getVar('PN'), task)
                 # Make sure sigdata is dumped before run printdiff
                 bb.error("%s -Snone" % cmd)
                 bb.error("Then:")
                 bb.error("%s -Sprintdiff\n" % cmd)
-            self.basehash[k] = basehash[k]
+            self.basehash[tid] = basehash[tid]
 
         self.taskdeps[fn] = taskdeps
         self.gendeps[fn] = gendeps
@@ -158,7 +170,7 @@
         #    self.dump_sigtask(fn, task, d.getVar("STAMP"), False)
 
         for task in taskdeps:
-            d.setVar("BB_BASEHASH_task-%s" % task, self.basehash[fn + "." + task])
+            d.setVar("BB_BASEHASH_task-%s" % task, self.basehash[fn + ":" + task])
 
     def rundep_check(self, fn, recipename, task, dep, depname, dataCache):
         # Return True if we should keep the dependency, False to drop it
@@ -178,33 +190,26 @@
             pass
         return taint
 
-    def get_taskhash(self, fn, task, deps, dataCache):
+    def get_taskhash(self, tid, deps, dataCache):
 
-        mc = ''
-        if fn.startswith('mc:'):
-            mc = fn.split(':')[1]
-        k = fn + "." + task
+        (mc, _, task, fn) = bb.runqueue.split_tid_mcfn(tid)
 
-        data = dataCache.basetaskhash[k]
-        self.basehash[k] = data
-        self.runtaskdeps[k] = []
-        self.file_checksum_values[k] = []
+        data = dataCache.basetaskhash[tid]
+        self.basehash[tid] = data
+        self.runtaskdeps[tid] = []
+        self.file_checksum_values[tid] = []
         recipename = dataCache.pkg_fn[fn]
         for dep in sorted(deps, key=clean_basepath):
-            pkgname = self.pkgnameextract.search(dep).group('fn')
-            if mc:
-                depmc = pkgname.split(':')[1]
-                if mc != depmc:
-                    continue
-            if dep.startswith("mc:") and not mc:
+            (depmc, _, deptaskname, depfn) = bb.runqueue.split_tid_mcfn(dep)
+            if mc != depmc:
                 continue
-            depname = dataCache.pkg_fn[pkgname]
+            depname = dataCache.pkg_fn[depfn]
             if not self.rundep_check(fn, recipename, task, dep, depname, dataCache):
                 continue
             if dep not in self.taskhash:
                 bb.fatal("%s is not in taskhash, caller isn't calling in dependency order?" % dep)
             data = data + self.get_unihash(dep)
-            self.runtaskdeps[k].append(dep)
+            self.runtaskdeps[tid].append(dep)
 
         if task in dataCache.file_checksums[fn]:
             if self.checksum_cache:
@@ -212,7 +217,7 @@
             else:
                 checksums = bb.fetch2.get_file_checksums(dataCache.file_checksums[fn][task], recipename)
             for (f,cs) in checksums:
-                self.file_checksum_values[k].append((f,cs))
+                self.file_checksum_values[tid].append((f,cs))
                 if cs:
                     data = data + cs
 
@@ -222,16 +227,16 @@
             import uuid
             taint = str(uuid.uuid4())
             data = data + taint
-            self.taints[k] = "nostamp:" + taint
+            self.taints[tid] = "nostamp:" + taint
 
         taint = self.read_taint(fn, task, dataCache.stamp[fn])
         if taint:
             data = data + taint
-            self.taints[k] = taint
-            logger.warning("%s is tainted from a forced run" % k)
+            self.taints[tid] = taint
+            logger.warning("%s is tainted from a forced run" % tid)
 
         h = hashlib.sha256(data.encode("utf-8")).hexdigest()
-        self.taskhash[k] = h
+        self.taskhash[tid] = h
         #d.setVar("BB_TASKHASH_task-%s" % task, taskhash[task])
         return h
 
@@ -244,17 +249,20 @@
             bb.fetch2.fetcher_parse_save()
             bb.fetch2.fetcher_parse_done()
 
+    def save_unitaskhashes(self):
+        self.unihash_cache.save(self.unitaskhashes)
+
     def dump_sigtask(self, fn, task, stampbase, runtime):
 
-        k = fn + "." + task
+        tid = fn + ":" + task
         referencestamp = stampbase
         if isinstance(runtime, str) and runtime.startswith("customfile"):
             sigfile = stampbase
             referencestamp = runtime[11:]
-        elif runtime and k in self.taskhash:
-            sigfile = stampbase + "." + task + ".sigdata" + "." + self.taskhash[k]
+        elif runtime and tid in self.taskhash:
+            sigfile = stampbase + "." + task + ".sigdata" + "." + self.taskhash[tid]
         else:
-            sigfile = stampbase + "." + task + ".sigbasedata" + "." + self.basehash[k]
+            sigfile = stampbase + "." + task + ".sigbasedata" + "." + self.basehash[tid]
 
         bb.utils.mkdirhier(os.path.dirname(sigfile))
 
@@ -263,7 +271,7 @@
         data['basewhitelist'] = self.basewhitelist
         data['taskwhitelist'] = self.taskwhitelist
         data['taskdeps'] = self.taskdeps[fn][task]
-        data['basehash'] = self.basehash[k]
+        data['basehash'] = self.basehash[tid]
         data['gendeps'] = {}
         data['varvals'] = {}
         data['varvals'][task] = self.lookupcache[fn][task]
@@ -273,30 +281,30 @@
             data['gendeps'][dep] = self.gendeps[fn][dep]
             data['varvals'][dep] = self.lookupcache[fn][dep]
 
-        if runtime and k in self.taskhash:
-            data['runtaskdeps'] = self.runtaskdeps[k]
-            data['file_checksum_values'] = [(os.path.basename(f), cs) for f,cs in self.file_checksum_values[k]]
+        if runtime and tid in self.taskhash:
+            data['runtaskdeps'] = self.runtaskdeps[tid]
+            data['file_checksum_values'] = [(os.path.basename(f), cs) for f,cs in self.file_checksum_values[tid]]
             data['runtaskhashes'] = {}
             for dep in data['runtaskdeps']:
                 data['runtaskhashes'][dep] = self.get_unihash(dep)
-            data['taskhash'] = self.taskhash[k]
+            data['taskhash'] = self.taskhash[tid]
 
         taint = self.read_taint(fn, task, referencestamp)
         if taint:
             data['taint'] = taint
 
-        if runtime and k in self.taints:
-            if 'nostamp:' in self.taints[k]:
-                data['taint'] = self.taints[k]
+        if runtime and tid in self.taints:
+            if 'nostamp:' in self.taints[tid]:
+                data['taint'] = self.taints[tid]
 
         computed_basehash = calc_basehash(data)
-        if computed_basehash != self.basehash[k]:
-            bb.error("Basehash mismatch %s versus %s for %s" % (computed_basehash, self.basehash[k], k))
-        if runtime and k in self.taskhash:
+        if computed_basehash != self.basehash[tid]:
+            bb.error("Basehash mismatch %s versus %s for %s" % (computed_basehash, self.basehash[tid], tid))
+        if runtime and tid in self.taskhash:
             computed_taskhash = calc_taskhash(data)
-            if computed_taskhash != self.taskhash[k]:
-                bb.error("Taskhash mismatch %s versus %s for %s" % (computed_taskhash, self.taskhash[k], k))
-                sigfile = sigfile.replace(self.taskhash[k], computed_taskhash)
+            if computed_taskhash != self.taskhash[tid]:
+                bb.error("Taskhash mismatch %s versus %s for %s" % (computed_taskhash, self.taskhash[tid], tid))
+                sigfile = sigfile.replace(self.taskhash[tid], computed_taskhash)
 
         fd, tmpfile = tempfile.mkstemp(dir=os.path.dirname(sigfile), prefix="sigtask.")
         try:
@@ -316,34 +324,33 @@
         if fn in self.taskdeps:
             for task in self.taskdeps[fn]:
                 tid = fn + ":" + task
-                (mc, _, _) = bb.runqueue.split_tid(tid)
-                k = fn + "." + task
-                if k not in self.taskhash:
+                mc = bb.runqueue.mc_from_tid(tid)
+                if tid not in self.taskhash:
                     continue
-                if dataCaches[mc].basetaskhash[k] != self.basehash[k]:
-                    bb.error("Bitbake's cached basehash does not match the one we just generated (%s)!" % k)
-                    bb.error("The mismatched hashes were %s and %s" % (dataCaches[mc].basetaskhash[k], self.basehash[k]))
+                if dataCaches[mc].basetaskhash[tid] != self.basehash[tid]:
+                    bb.error("Bitbake's cached basehash does not match the one we just generated (%s)!" % tid)
+                    bb.error("The mismatched hashes were %s and %s" % (dataCaches[mc].basetaskhash[tid], self.basehash[tid]))
                 self.dump_sigtask(fn, task, dataCaches[mc].stamp[fn], True)
 
 class SignatureGeneratorBasicHash(SignatureGeneratorBasic):
     name = "basichash"
 
-    def get_stampfile_hash(self, task):
-        if task in self.taskhash:
-            return self.taskhash[task]
+    def get_stampfile_hash(self, tid):
+        if tid in self.taskhash:
+            return self.taskhash[tid]
 
         # If task is not in basehash, then error
-        return self.basehash[task]
+        return self.basehash[tid]
 
     def stampfile(self, stampbase, fn, taskname, extrainfo, clean=False):
         if taskname != "do_setscene" and taskname.endswith("_setscene"):
-            k = fn + "." + taskname[:-9]
+            tid = fn + ":" + taskname[:-9]
         else:
-            k = fn + "." + taskname
+            tid = fn + ":" + taskname
         if clean:
             h = "*"
         else:
-            h = self.get_stampfile_hash(k)
+            h = self.get_stampfile_hash(tid)
 
         return ("%s.%s.%s.%s" % (stampbase, taskname, h, extrainfo)).rstrip('.')
 
@@ -354,6 +361,187 @@
         bb.note("Tainting hash to force rebuild of task %s, %s" % (fn, task))
         bb.build.write_taint(task, d, fn)
 
+class SignatureGeneratorUniHashMixIn(object):
+    def get_taskdata(self):
+        return (self.server, self.method) + super().get_taskdata()
+
+    def set_taskdata(self, data):
+        self.server, self.method = data[:2]
+        super().set_taskdata(data[2:])
+
+    def __get_task_unihash_key(self, tid):
+        # TODO: The key only *needs* to be the taskhash, the tid is just
+        # convenient
+        return '%s:%s' % (tid, self.taskhash[tid])
+
+    def get_stampfile_hash(self, tid):
+        if tid in self.taskhash:
+            # If a unique hash is reported, use it as the stampfile hash. This
+            # ensures that if a task won't be re-run if the taskhash changes,
+            # but it would result in the same output hash
+            unihash = self.unitaskhashes.get(self.__get_task_unihash_key(tid), None)
+            if unihash is not None:
+                return unihash
+
+        return super().get_stampfile_hash(tid)
+
+    def set_unihash(self, tid, unihash):
+        self.unitaskhashes[self.__get_task_unihash_key(tid)] = unihash
+
+    def get_unihash(self, tid):
+        import urllib
+        import json
+
+        taskhash = self.taskhash[tid]
+
+        key = self.__get_task_unihash_key(tid)
+
+        # TODO: This cache can grow unbounded. It probably only needs to keep
+        # for each task
+        unihash = self.unitaskhashes.get(key, None)
+        if unihash is not None:
+            return unihash
+
+        # In the absence of being able to discover a unique hash from the
+        # server, make it be equivalent to the taskhash. The unique "hash" only
+        # really needs to be a unique string (not even necessarily a hash), but
+        # making it match the taskhash has a few advantages:
+        #
+        # 1) All of the sstate code that assumes hashes can be the same
+        # 2) It provides maximal compatibility with builders that don't use
+        #    an equivalency server
+        # 3) The value is easy for multiple independent builders to derive the
+        #    same unique hash from the same input. This means that if the
+        #    independent builders find the same taskhash, but it isn't reported
+        #    to the server, there is a better chance that they will agree on
+        #    the unique hash.
+        unihash = taskhash
+
+        try:
+            url = '%s/v1/equivalent?%s' % (self.server,
+                    urllib.parse.urlencode({'method': self.method, 'taskhash': self.taskhash[tid]}))
+
+            request = urllib.request.Request(url)
+            response = urllib.request.urlopen(request)
+            data = response.read().decode('utf-8')
+
+            json_data = json.loads(data)
+
+            if json_data:
+                unihash = json_data['unihash']
+                # A unique hash equal to the taskhash is not very interesting,
+                # so it is reported it at debug level 2. If they differ, that
+                # is much more interesting, so it is reported at debug level 1
+                bb.debug((1, 2)[unihash == taskhash], 'Found unihash %s in place of %s for %s from %s' % (unihash, taskhash, tid, self.server))
+            else:
+                bb.debug(2, 'No reported unihash for %s:%s from %s' % (tid, taskhash, self.server))
+        except urllib.error.URLError as e:
+            bb.warn('Failure contacting Hash Equivalence Server %s: %s' % (self.server, str(e)))
+        except (KeyError, json.JSONDecodeError) as e:
+            bb.warn('Poorly formatted response from %s: %s' % (self.server, str(e)))
+
+        self.unitaskhashes[key] = unihash
+        return unihash
+
+    def report_unihash(self, path, task, d):
+        import urllib
+        import json
+        import tempfile
+        import base64
+        import importlib
+
+        taskhash = d.getVar('BB_TASKHASH')
+        unihash = d.getVar('BB_UNIHASH')
+        report_taskdata = d.getVar('SSTATE_HASHEQUIV_REPORT_TASKDATA') == '1'
+        tempdir = d.getVar('T')
+        fn = d.getVar('BB_FILENAME')
+        key = fn + ':do_' + task + ':' + taskhash
+
+        # Sanity checks
+        cache_unihash = self.unitaskhashes.get(key, None)
+        if cache_unihash is None:
+            bb.fatal('%s not in unihash cache. Please report this error' % key)
+
+        if cache_unihash != unihash:
+            bb.fatal("Cache unihash %s doesn't match BB_UNIHASH %s" % (cache_unihash, unihash))
+
+        sigfile = None
+        sigfile_name = "depsig.do_%s.%d" % (task, os.getpid())
+        sigfile_link = "depsig.do_%s" % task
+
+        try:
+            sigfile = open(os.path.join(tempdir, sigfile_name), 'w+b')
+
+            locs = {'path': path, 'sigfile': sigfile, 'task': task, 'd': d}
+
+            if "." in self.method:
+                (module, method) = self.method.rsplit('.', 1)
+                locs['method'] = getattr(importlib.import_module(module), method)
+                outhash = bb.utils.better_eval('method(path, sigfile, task, d)', locs)
+            else:
+                outhash = bb.utils.better_eval(self.method + '(path, sigfile, task, d)', locs)
+
+            try:
+                url = '%s/v1/equivalent' % self.server
+                task_data = {
+                    'taskhash': taskhash,
+                    'method': self.method,
+                    'outhash': outhash,
+                    'unihash': unihash,
+                    'owner': d.getVar('SSTATE_HASHEQUIV_OWNER')
+                    }
+
+                if report_taskdata:
+                    sigfile.seek(0)
+
+                    task_data['PN'] = d.getVar('PN')
+                    task_data['PV'] = d.getVar('PV')
+                    task_data['PR'] = d.getVar('PR')
+                    task_data['task'] = task
+                    task_data['outhash_siginfo'] = sigfile.read().decode('utf-8')
+
+                headers = {'content-type': 'application/json'}
+
+                request = urllib.request.Request(url, json.dumps(task_data).encode('utf-8'), headers)
+                response = urllib.request.urlopen(request)
+                data = response.read().decode('utf-8')
+
+                json_data = json.loads(data)
+                new_unihash = json_data['unihash']
+
+                if new_unihash != unihash:
+                    bb.debug(1, 'Task %s unihash changed %s -> %s by server %s' % (taskhash, unihash, new_unihash, self.server))
+                    bb.event.fire(bb.runqueue.taskUniHashUpdate(fn + ':do_' + task, new_unihash), d)
+                else:
+                    bb.debug(1, 'Reported task %s as unihash %s to %s' % (taskhash, unihash, self.server))
+            except urllib.error.URLError as e:
+                bb.warn('Failure contacting Hash Equivalence Server %s: %s' % (self.server, str(e)))
+            except (KeyError, json.JSONDecodeError) as e:
+                bb.warn('Poorly formatted response from %s: %s' % (self.server, str(e)))
+        finally:
+            if sigfile:
+                sigfile.close()
+
+                sigfile_link_path = os.path.join(tempdir, sigfile_link)
+                bb.utils.remove(sigfile_link_path)
+
+                try:
+                    os.symlink(sigfile_name, sigfile_link_path)
+                except OSError:
+                    pass
+
+
+#
+# Dummy class used for bitbake-selftest
+#
+class SignatureGeneratorTestEquivHash(SignatureGeneratorUniHashMixIn, SignatureGeneratorBasicHash):
+    name = "TestEquivHash"
+    def init_rundepcheck(self, data):
+        super().init_rundepcheck(data)
+        self.server = "http://" + data.getVar('BB_HASHSERVE')
+        self.method = "sstate_output_hash"
+
+
 def dump_this_task(outfile, d):
     import bb.parse
     fn = d.getVar("BB_FILENAME")
diff --git a/poky/bitbake/lib/bb/tests/data.py b/poky/bitbake/lib/bb/tests/data.py
index 3cf5abe..a9b0bdb 100644
--- a/poky/bitbake/lib/bb/tests/data.py
+++ b/poky/bitbake/lib/bb/tests/data.py
@@ -466,7 +466,7 @@
             tasklist, gendeps, lookupcache = bb.data.generate_dependencies(d)
             taskdeps, basehash = bb.data.generate_dependency_hash(tasklist, gendeps, lookupcache, set(), "somefile")
             bb.warn(str(lookupcache))
-            return basehash["somefile." + taskname]
+            return basehash["somefile:" + taskname]
 
         d = bb.data.init()
         d.setVar("__BBTASKS", ["mytask"])
diff --git a/poky/bitbake/lib/bb/tests/runqueue-tests/classes/base.bbclass b/poky/bitbake/lib/bb/tests/runqueue-tests/classes/base.bbclass
index 5b87e20..b57650d 100644
--- a/poky/bitbake/lib/bb/tests/runqueue-tests/classes/base.bbclass
+++ b/poky/bitbake/lib/bb/tests/runqueue-tests/classes/base.bbclass
@@ -5,18 +5,30 @@
     import time
 
     thistask = d.expand("${PN}:${BB_CURRENTTASK}")
-    with open(d.expand("${TOPDIR}/%s.run") % thistask, "a+") as f:
-        f.write("\n")
+    stampname = d.expand("${TOPDIR}/%s.run" % thistask)
+    with open(stampname, "a+") as f:
+        f.write(d.getVar("BB_UNIHASH") + "\n")
 
     if d.getVar("BB_CURRENT_MC") != "default":
         thistask = d.expand("${BB_CURRENT_MC}:${PN}:${BB_CURRENTTASK}")
     if thistask in d.getVar("SLOWTASKS").split():
         bb.note("Slowing task %s" % thistask)
         time.sleep(0.5)
+    if d.getVar("BB_HASHSERVE"):
+        task = d.getVar("BB_CURRENTTASK")
+        if task in ['package', 'package_qa', 'packagedata', 'package_write_ipk', 'package_write_rpm', 'populate_lic', 'populate_sysroot']:
+            bb.parse.siggen.report_unihash(os.getcwd(), d.getVar("BB_CURRENTTASK"), d)
 
     with open(d.expand("${TOPDIR}/task.log"), "a+") as f:
         f.write(thistask + "\n")
 
+
+def sstate_output_hash(path, sigfile, task, d):
+    import hashlib
+    h = hashlib.sha256()
+    h.update(d.expand("${PN}:${BB_CURRENTTASK}").encode('utf-8'))
+    return h.hexdigest()
+
 python do_fetch() {
     # fetch
     stamptask(d)
@@ -216,27 +228,35 @@
 
 BB_HASHCHECK_FUNCTION = "sstate_checkhashes"
 
-def sstate_checkhashes(sq_fn, sq_task, sq_hash, sq_hashfn, d, siginfo=False, *, sq_unihash=None):
+def sstate_checkhashes(sq_data, d, siginfo=False, currentcount=0, **kwargs):
 
-    ret = []
-    missed = []
+    found = set()
+    missed = set()
 
     valid = d.getVar("SSTATEVALID").split()
 
-    for task in range(len(sq_fn)):
-        n = os.path.basename(sq_fn[task]).rsplit(".", 1)[0] + ":" + sq_task[task]
+    for tid in sorted(sq_data['hash']):
+        n = os.path.basename(bb.runqueue.fn_from_tid(tid)).split(".")[0] + ":do_" + bb.runqueue.taskname_from_tid(tid)[3:]
+        print(n)
+        stampfile = d.expand("${TOPDIR}/%s.run" % n.replace("do_", ""))
         if n in valid:
             bb.note("SState: Found valid sstate for %s" % n)
-            ret.append(task)
-        elif os.path.exists(d.expand("${TOPDIR}/%s.run" % n.replace("do_", ""))):
-            bb.note("SState: Found valid sstate for %s (already run)" % n)
-            ret.append(task)
+            found.add(tid)
+        elif n + ":" + sq_data['hash'][tid] in valid:
+            bb.note("SState: Found valid sstate for %s" % n)
+            found.add(tid)
+        elif os.path.exists(stampfile):
+            with open(stampfile, "r") as f:
+                hash = f.readline().strip()
+            if hash == sq_data['hash'][tid]:
+                bb.note("SState: Found valid sstate for %s (already run)" % n)
+                found.add(tid)
+            else:
+                bb.note("SState: sstate hash didn't match previous run for %s (%s vs %s)" % (n, sq_data['hash'][tid], hash))
+                missed.add(tid)
         else:
-            missed.append(task)
-            bb.note("SState: Found no valid sstate for %s" % n)
+            missed.add(tid)
+            bb.note("SState: Found no valid sstate for %s (%s)" % (n, sq_data['hash'][tid]))
 
-    if hasattr(bb.parse.siggen, "checkhashes"):
-        bb.parse.siggen.checkhashes(missed, ret, sq_fn, sq_task, sq_hash, sq_hashfn, d)
-
-    return ret
+    return found
 
diff --git a/poky/bitbake/lib/bb/tests/runqueue-tests/conf/bitbake.conf b/poky/bitbake/lib/bb/tests/runqueue-tests/conf/bitbake.conf
index 96ee1cd..5e451fc 100644
--- a/poky/bitbake/lib/bb/tests/runqueue-tests/conf/bitbake.conf
+++ b/poky/bitbake/lib/bb/tests/runqueue-tests/conf/bitbake.conf
@@ -11,6 +11,6 @@
 T = "${TMPDIR}/workdir/${PN}/temp"
 BB_NUMBER_THREADS = "4"
 
-BB_HASHBASE_WHITELIST = "BB_CURRENT_MC"
+BB_HASHBASE_WHITELIST = "BB_CURRENT_MC BB_HASHSERVE TMPDIR TOPDIR SLOWTASKS SSTATEVALID FILE"
 
 include conf/multiconfig/${BB_CURRENT_MC}.conf
diff --git a/poky/bitbake/lib/bb/tests/runqueue-tests/recipes/e1.bb b/poky/bitbake/lib/bb/tests/runqueue-tests/recipes/e1.bb
new file mode 100644
index 0000000..1588bc8
--- /dev/null
+++ b/poky/bitbake/lib/bb/tests/runqueue-tests/recipes/e1.bb
@@ -0,0 +1 @@
+DEPENDS = "b1"
\ No newline at end of file
diff --git a/poky/bitbake/lib/bb/tests/runqueue.py b/poky/bitbake/lib/bb/tests/runqueue.py
index f22ad4b..c7f5e55 100644
--- a/poky/bitbake/lib/bb/tests/runqueue.py
+++ b/poky/bitbake/lib/bb/tests/runqueue.py
@@ -25,7 +25,7 @@
     a1_sstatevalid = "a1:do_package a1:do_package_qa a1:do_packagedata a1:do_package_write_ipk a1:do_package_write_rpm a1:do_populate_lic a1:do_populate_sysroot"
     b1_sstatevalid = "b1:do_package b1:do_package_qa b1:do_packagedata b1:do_package_write_ipk b1:do_package_write_rpm b1:do_populate_lic b1:do_populate_sysroot"
 
-    def run_bitbakecmd(self, cmd, builddir, sstatevalid="", slowtasks="", extraenv=None):
+    def run_bitbakecmd(self, cmd, builddir, sstatevalid="", slowtasks="", extraenv=None, cleanup=False):
         env = os.environ.copy()
         env["BBPATH"] = os.path.realpath(os.path.join(os.path.dirname(__file__), "runqueue-tests"))
         env["BB_ENV_EXTRAWHITE"] = "SSTATEVALID SLOWTASKS"
@@ -37,11 +37,16 @@
                 env["BB_ENV_EXTRAWHITE"] = env["BB_ENV_EXTRAWHITE"] + " " + k
         try:
             output = subprocess.check_output(cmd, env=env, stderr=subprocess.STDOUT,universal_newlines=True, cwd=builddir)
+            print(output)
         except subprocess.CalledProcessError as e:
             self.fail("Command %s failed with %s" % (cmd, e.output))
         tasks = []
-        with open(builddir + "/task.log", "r") as f:
-            tasks = [line.rstrip() for line in f]
+        tasklog = builddir + "/task.log"
+        if os.path.exists(tasklog):
+            with open(tasklog, "r") as f:
+                tasks = [line.rstrip() for line in f]
+            if cleanup:
+                os.remove(tasklog)
         return tasks
 
     def test_no_setscenevalid(self):
@@ -226,3 +231,166 @@
                 expected.remove(x)
             self.assertEqual(set(tasks), set(expected))
 
+
+    def test_hashserv_single(self):
+        with tempfile.TemporaryDirectory(prefix="runqueuetest") as tempdir:
+            extraenv = {
+                "BB_HASHSERVE" : "localhost:0",
+                "BB_SIGNATURE_HANDLER" : "TestEquivHash"
+            }
+            cmd = ["bitbake", "a1", "b1"]
+            setscenetasks = ['package_write_ipk_setscene', 'package_write_rpm_setscene', 'packagedata_setscene',
+                             'populate_sysroot_setscene', 'package_qa_setscene']
+            sstatevalid = ""
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:' + x for x in self.alltasks] + ['b1:' + x for x in self.alltasks]
+            self.assertEqual(set(tasks), set(expected))
+            cmd = ["bitbake", "a1", "-c", "install", "-f"]
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:install']
+            self.assertEqual(set(tasks), set(expected))
+            cmd = ["bitbake", "a1", "b1"]
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:populate_sysroot', 'a1:package', 'a1:package_write_rpm_setscene', 'a1:packagedata_setscene',
+                        'a1:package_write_ipk_setscene', 'a1:package_qa_setscene']
+            self.assertEqual(set(tasks), set(expected))
+
+    def test_hashserv_double(self):
+        with tempfile.TemporaryDirectory(prefix="runqueuetest") as tempdir:
+            extraenv = {
+                "BB_HASHSERVE" : "localhost:0",
+                "BB_SIGNATURE_HANDLER" : "TestEquivHash"
+            }
+            cmd = ["bitbake", "a1", "b1", "e1"]
+            setscenetasks = ['package_write_ipk_setscene', 'package_write_rpm_setscene', 'packagedata_setscene',
+                             'populate_sysroot_setscene', 'package_qa_setscene']
+            sstatevalid = ""
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:' + x for x in self.alltasks] + ['b1:' + x for x in self.alltasks] + ['e1:' + x for x in self.alltasks]
+            self.assertEqual(set(tasks), set(expected))
+            cmd = ["bitbake", "a1", "b1", "-c", "install", "-fn"]
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            cmd = ["bitbake", "e1"]
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:package', 'a1:install', 'b1:package', 'b1:install', 'a1:populate_sysroot', 'b1:populate_sysroot',
+                        'a1:package_write_ipk_setscene', 'b1:packagedata_setscene', 'b1:package_write_rpm_setscene',
+                        'a1:package_write_rpm_setscene', 'b1:package_write_ipk_setscene', 'a1:packagedata_setscene']
+            self.assertEqual(set(tasks), set(expected))
+
+
+    def test_hashserv_multiple_setscene(self):
+        # Runs e1:do_package_setscene twice
+        with tempfile.TemporaryDirectory(prefix="runqueuetest") as tempdir:
+            extraenv = {
+                "BB_HASHSERVE" : "localhost:0",
+                "BB_SIGNATURE_HANDLER" : "TestEquivHash"
+            }
+            cmd = ["bitbake", "a1", "b1", "e1"]
+            setscenetasks = ['package_write_ipk_setscene', 'package_write_rpm_setscene', 'packagedata_setscene',
+                             'populate_sysroot_setscene', 'package_qa_setscene']
+            sstatevalid = ""
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:' + x for x in self.alltasks] + ['b1:' + x for x in self.alltasks] + ['e1:' + x for x in self.alltasks]
+            self.assertEqual(set(tasks), set(expected))
+            cmd = ["bitbake", "a1", "b1", "-c", "install", "-fn"]
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            cmd = ["bitbake", "e1"]
+            sstatevalid = "e1:do_package"
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True, slowtasks="a1:populate_sysroot b1:populate_sysroot")
+            expected = ['a1:package', 'a1:install', 'b1:package', 'b1:install', 'a1:populate_sysroot', 'b1:populate_sysroot',
+                        'a1:package_write_ipk_setscene', 'b1:packagedata_setscene', 'b1:package_write_rpm_setscene',
+                        'a1:package_write_rpm_setscene', 'b1:package_write_ipk_setscene', 'a1:packagedata_setscene',
+                        'e1:package_setscene']
+            self.assertEqual(set(tasks), set(expected))
+            for i in expected:
+                if i in ["e1:package_setscene"]:
+                    self.assertEqual(tasks.count(i), 4, "%s not in task list four times" % i)
+                else:
+                    self.assertEqual(tasks.count(i), 1, "%s not in task list once" % i)
+
+    def test_hashserv_partial_match(self):
+        # e1:do_package matches initial built but not second hash value
+        with tempfile.TemporaryDirectory(prefix="runqueuetest") as tempdir:
+            extraenv = {
+                "BB_HASHSERVE" : "localhost:0",
+                "BB_SIGNATURE_HANDLER" : "TestEquivHash"
+            }
+            cmd = ["bitbake", "a1", "b1"]
+            setscenetasks = ['package_write_ipk_setscene', 'package_write_rpm_setscene', 'packagedata_setscene',
+                             'populate_sysroot_setscene', 'package_qa_setscene']
+            sstatevalid = ""
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:' + x for x in self.alltasks] + ['b1:' + x for x in self.alltasks]
+            self.assertEqual(set(tasks), set(expected))
+            with open(tempdir + "/stamps/a1.do_install.taint", "w") as f:
+               f.write("d460a29e-903f-4b76-a96b-3bcc22a65994")
+            with open(tempdir + "/stamps/b1.do_install.taint", "w") as f:
+               f.write("ed36d46a-2977-458a-b3de-eef885bc1817")
+            cmd = ["bitbake", "e1"]
+            sstatevalid = "e1:do_package:685e69a026b2f029483fdefe6a11e1e06641dd2a0f6f86e27b9b550f8f21229d"
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:package', 'a1:install', 'b1:package', 'b1:install', 'a1:populate_sysroot', 'b1:populate_sysroot',
+                        'a1:package_write_ipk_setscene', 'b1:packagedata_setscene', 'b1:package_write_rpm_setscene',
+                        'a1:package_write_rpm_setscene', 'b1:package_write_ipk_setscene', 'a1:packagedata_setscene',
+                        'e1:package_setscene'] + ['e1:' + x for x in self.alltasks]
+            expected.remove('e1:package')
+            self.assertEqual(set(tasks), set(expected))
+
+    def test_hashserv_partial_match2(self):
+        # e1:do_package + e1:do_populate_sysroot matches initial built but not second hash value
+        with tempfile.TemporaryDirectory(prefix="runqueuetest") as tempdir:
+            extraenv = {
+                "BB_HASHSERVE" : "localhost:0",
+                "BB_SIGNATURE_HANDLER" : "TestEquivHash"
+            }
+            cmd = ["bitbake", "a1", "b1"]
+            setscenetasks = ['package_write_ipk_setscene', 'package_write_rpm_setscene', 'packagedata_setscene',
+                             'populate_sysroot_setscene', 'package_qa_setscene']
+            sstatevalid = ""
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:' + x for x in self.alltasks] + ['b1:' + x for x in self.alltasks]
+            self.assertEqual(set(tasks), set(expected))
+            with open(tempdir + "/stamps/a1.do_install.taint", "w") as f:
+               f.write("d460a29e-903f-4b76-a96b-3bcc22a65994")
+            with open(tempdir + "/stamps/b1.do_install.taint", "w") as f:
+               f.write("ed36d46a-2977-458a-b3de-eef885bc1817")
+            cmd = ["bitbake", "e1"]
+            sstatevalid = "e1:do_package:685e69a026b2f029483fdefe6a11e1e06641dd2a0f6f86e27b9b550f8f21229d e1:do_populate_sysroot:ef7dc0e2dd55d0534e75cba50731ff42f949818b6f29a65d72bc05856e56711d"
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:package', 'a1:install', 'b1:package', 'b1:install', 'a1:populate_sysroot', 'b1:populate_sysroot',
+                        'a1:package_write_ipk_setscene', 'b1:packagedata_setscene', 'b1:package_write_rpm_setscene',
+                        'a1:package_write_rpm_setscene', 'b1:package_write_ipk_setscene', 'a1:packagedata_setscene',
+                        'e1:package_setscene', 'e1:populate_sysroot_setscene', 'e1:build', 'e1:package_qa', 'e1:package_write_rpm', 'e1:package_write_ipk', 'e1:packagedata']
+            self.assertEqual(set(tasks), set(expected))
+
+    def test_hashserv_partial_match3(self):
+        # e1:do_package is valid for a1 but not after b1
+        # In former buggy code, this triggered e1:do_fetch, then e1:do_populate_sysroot to run
+        # with none of the intermediate tasks which is a serious bug
+        with tempfile.TemporaryDirectory(prefix="runqueuetest") as tempdir:
+            extraenv = {
+                "BB_HASHSERVE" : "localhost:0",
+                "BB_SIGNATURE_HANDLER" : "TestEquivHash"
+            }
+            cmd = ["bitbake", "a1", "b1"]
+            setscenetasks = ['package_write_ipk_setscene', 'package_write_rpm_setscene', 'packagedata_setscene',
+                             'populate_sysroot_setscene', 'package_qa_setscene']
+            sstatevalid = ""
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True)
+            expected = ['a1:' + x for x in self.alltasks] + ['b1:' + x for x in self.alltasks]
+            self.assertEqual(set(tasks), set(expected))
+            with open(tempdir + "/stamps/a1.do_install.taint", "w") as f:
+               f.write("d460a29e-903f-4b76-a96b-3bcc22a65994")
+            with open(tempdir + "/stamps/b1.do_install.taint", "w") as f:
+               f.write("ed36d46a-2977-458a-b3de-eef885bc1817")
+            cmd = ["bitbake", "e1", "-DD"]
+            sstatevalid = "e1:do_package:af056eae12a733a6a8c4f4da8c6757e588e13565852c94e2aad4d953a3989c13 e1:do_package:a3677703db82b22d28d57c1820a47851dd780104580863f5bd32e66e003a779d"
+            tasks = self.run_bitbakecmd(cmd, tempdir, sstatevalid, extraenv=extraenv, cleanup=True, slowtasks="e1:fetch b1:install")
+            expected = ['a1:package', 'a1:install', 'b1:package', 'b1:install', 'a1:populate_sysroot', 'b1:populate_sysroot',
+                        'a1:package_write_ipk_setscene', 'b1:packagedata_setscene', 'b1:package_write_rpm_setscene',
+                        'a1:package_write_rpm_setscene', 'b1:package_write_ipk_setscene', 'a1:packagedata_setscene',
+                        'e1:package_setscene']  + ['e1:' + x for x in self.alltasks]
+            expected.remove('e1:package')
+            self.assertEqual(set(tasks), set(expected))
+
+
diff --git a/poky/bitbake/lib/bb/ui/knotty.py b/poky/bitbake/lib/bb/ui/knotty.py
index 1c72aa2..35736ad 100644
--- a/poky/bitbake/lib/bb/ui/knotty.py
+++ b/poky/bitbake/lib/bb/ui/knotty.py
@@ -689,17 +689,27 @@
             if params.observe_only:
                 print("\nKeyboard Interrupt, exiting observer...")
                 main.shutdown = 2
-            if not params.observe_only and main.shutdown == 1:
+
+            def state_force_shutdown():
                 print("\nSecond Keyboard Interrupt, stopping...\n")
                 _, error = server.runCommand(["stateForceShutdown"])
                 if error:
                     logger.error("Unable to cleanly stop: %s" % error)
+
+            if not params.observe_only and main.shutdown == 1:
+                state_force_shutdown()
+
             if not params.observe_only and main.shutdown == 0:
                 print("\nKeyboard Interrupt, closing down...\n")
                 interrupted = True
-                _, error = server.runCommand(["stateShutdown"])
-                if error:
-                    logger.error("Unable to cleanly shutdown: %s" % error)
+                # Capture the second KeyboardInterrupt during stateShutdown is running
+                try:
+                    _, error = server.runCommand(["stateShutdown"])
+                    if error:
+                        logger.error("Unable to cleanly shutdown: %s" % error)
+                except KeyboardInterrupt:
+                    state_force_shutdown()
+
             main.shutdown = main.shutdown + 1
             pass
         except Exception as e:
diff --git a/poky/bitbake/lib/bb/utils.py b/poky/bitbake/lib/bb/utils.py
index ed19825..0618e46 100644
--- a/poky/bitbake/lib/bb/utils.py
+++ b/poky/bitbake/lib/bb/utils.py
@@ -394,7 +394,7 @@
         code = better_compile(code, realfile, realfile)
     try:
         exec(code, get_context(), context)
-    except (bb.BBHandledException, bb.parse.SkipRecipe, bb.build.FuncFailed, bb.data_smart.ExpansionError):
+    except (bb.BBHandledException, bb.parse.SkipRecipe, bb.data_smart.ExpansionError):
         # Error already shown so passthrough, no need for traceback
         raise
     except Exception as e: