diff --git a/poky/bitbake/lib/bb/__init__.py b/poky/bitbake/lib/bb/__init__.py
index b8333bd..6b470aa 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__ = "2.0.0"
+__version__ = "2.0.1"
 
 import sys
 if sys.version_info < (3, 6, 0):
diff --git a/poky/bitbake/lib/bb/cache.py b/poky/bitbake/lib/bb/cache.py
index 92e9a3c..988c596 100644
--- a/poky/bitbake/lib/bb/cache.py
+++ b/poky/bitbake/lib/bb/cache.py
@@ -24,6 +24,7 @@
 import bb.utils
 from bb import PrefixLoggerAdapter
 import re
+import shutil
 
 logger = logging.getLogger("BitBake.Cache")
 
@@ -998,3 +999,11 @@
             p.dump([data, self.cacheversion])
 
         bb.utils.unlockfile(glf)
+
+    def copyfile(self, target):
+        if not self.cachefile:
+            return
+
+        glf = bb.utils.lockfile(self.cachefile + ".lock")
+        shutil.copy(self.cachefile, target)
+        bb.utils.unlockfile(glf)
diff --git a/poky/bitbake/lib/bb/cooker.py b/poky/bitbake/lib/bb/cooker.py
index 6da9291..2adf4d2 100644
--- a/poky/bitbake/lib/bb/cooker.py
+++ b/poky/bitbake/lib/bb/cooker.py
@@ -13,7 +13,6 @@
 import itertools
 import logging
 import multiprocessing
-import sre_constants
 import threading
 from io import StringIO, UnsupportedOperation
 from contextlib import closing
@@ -1907,7 +1906,7 @@
                 try:
                     re.compile(mask)
                     bbmasks.append(mask)
-                except sre_constants.error:
+                except re.error:
                     collectlog.critical("BBMASK contains an invalid regular expression, ignoring: %s" % mask)
 
             # Then validate the combined regular expressions. This should never
@@ -1915,7 +1914,7 @@
             bbmask = "|".join(bbmasks)
             try:
                 bbmask_compiled = re.compile(bbmask)
-            except sre_constants.error:
+            except re.error:
                 collectlog.critical("BBMASK is not a valid regular expression, ignoring: %s" % bbmask)
                 bbmask = None
 
diff --git a/poky/bitbake/lib/bb/event.py b/poky/bitbake/lib/bb/event.py
index df02055..9766860 100644
--- a/poky/bitbake/lib/bb/event.py
+++ b/poky/bitbake/lib/bb/event.py
@@ -132,8 +132,14 @@
     if not _uiready:
         from bb.msg import BBLogFormatter
         # Flush any existing buffered content
-        sys.stdout.flush()
-        sys.stderr.flush()
+        try:
+            sys.stdout.flush()
+        except:
+            pass
+        try:
+            sys.stderr.flush()
+        except:
+            pass
         stdout = logging.StreamHandler(sys.stdout)
         stderr = logging.StreamHandler(sys.stderr)
         formatter = BBLogFormatter("%(levelname)s: %(message)s")
diff --git a/poky/bitbake/lib/bb/fetch2/git.py b/poky/bitbake/lib/bb/fetch2/git.py
index 23f8c0d..07b3d9a 100644
--- a/poky/bitbake/lib/bb/fetch2/git.py
+++ b/poky/bitbake/lib/bb/fetch2/git.py
@@ -353,10 +353,15 @@
         if ud.shallow and os.path.exists(ud.fullshallow) and self.need_update(ud, d):
             ud.localpath = ud.fullshallow
             return
-        elif os.path.exists(ud.fullmirror) and not os.path.exists(ud.clonedir):
-            bb.utils.mkdirhier(ud.clonedir)
-            runfetchcmd("tar -xzf %s" % ud.fullmirror, d, workdir=ud.clonedir)
-
+        elif os.path.exists(ud.fullmirror) and self.need_update(ud, d):
+            if not os.path.exists(ud.clonedir):
+                bb.utils.mkdirhier(ud.clonedir)
+                runfetchcmd("tar -xzf %s" % ud.fullmirror, d, workdir=ud.clonedir)
+            else:
+                tmpdir = tempfile.mkdtemp(dir=d.getVar('DL_DIR'))
+                runfetchcmd("tar -xzf %s" % ud.fullmirror, d, workdir=tmpdir)
+                fetch_cmd = "LANG=C %s fetch -f --progress %s " % (ud.basecmd, shlex.quote(tmpdir))
+                runfetchcmd(fetch_cmd, d, workdir=ud.clonedir)
         repourl = self._get_repo_url(ud)
 
         # If the repo still doesn't exist, fallback to cloning it
diff --git a/poky/bitbake/lib/bb/fetch2/wget.py b/poky/bitbake/lib/bb/fetch2/wget.py
index b3a3de5..b2b542e 100644
--- a/poky/bitbake/lib/bb/fetch2/wget.py
+++ b/poky/bitbake/lib/bb/fetch2/wget.py
@@ -106,10 +106,9 @@
 
         fetchcmd = self.basecmd
 
-        if 'downloadfilename' in ud.parm:
-            localpath = os.path.join(d.getVar("DL_DIR"), ud.localfile)
-            bb.utils.mkdirhier(os.path.dirname(localpath))
-            fetchcmd += " -O %s" % shlex.quote(localpath)
+        localpath = os.path.join(d.getVar("DL_DIR"), ud.localfile) + ".tmp"
+        bb.utils.mkdirhier(os.path.dirname(localpath))
+        fetchcmd += " -O %s" % shlex.quote(localpath)
 
         if ud.user and ud.pswd:
             fetchcmd += " --auth-no-challenge"
@@ -133,6 +132,10 @@
 
         self._runwget(ud, d, fetchcmd, False)
 
+        # Remove the ".tmp" and move the file into position atomically
+        # Our lock prevents multiple writers but mirroring code may grab incomplete files
+        os.rename(localpath, localpath[:-4])
+
         # Sanity check since wget can pretend it succeed when it didn't
         # Also, this used to happen if sourceforge sent us to the mirror page
         if not os.path.exists(ud.localpath):
diff --git a/poky/bitbake/lib/bb/runqueue.py b/poky/bitbake/lib/bb/runqueue.py
index f34f156..1e47fe7 100644
--- a/poky/bitbake/lib/bb/runqueue.py
+++ b/poky/bitbake/lib/bb/runqueue.py
@@ -2299,6 +2299,9 @@
                     self.rqdata.runtaskentries[hashtid].unihash = unihash
                     bb.parse.siggen.set_unihash(hashtid, unihash)
                     toprocess.add(hashtid)
+                if torehash:
+                    # Need to save after set_unihash above
+                    bb.parse.siggen.save_unitaskhashes()
 
         # Work out all tasks which depend upon these
         total = set()
diff --git a/poky/bitbake/lib/bb/server/process.py b/poky/bitbake/lib/bb/server/process.py
index 613956f..43790b6 100644
--- a/poky/bitbake/lib/bb/server/process.py
+++ b/poky/bitbake/lib/bb/server/process.py
@@ -437,6 +437,7 @@
         self.socket_connection = sock
 
     def terminate(self):
+        self.events.close()
         self.socket_connection.close()
         self.connection.connection.close()
         self.connection.recv.close()
@@ -662,23 +663,18 @@
         self.reader = ConnectionReader(readfd)
 
         self.t = threading.Thread()
-        self.t.daemon = True
         self.t.run = self.startCallbackHandler
         self.t.start()
 
     def getEvent(self):
-        self.eventQueueLock.acquire()
+        with self.eventQueueLock:
+            if len(self.eventQueue) == 0:
+                return None
 
-        if len(self.eventQueue) == 0:
-            self.eventQueueLock.release()
-            return None
+            item = self.eventQueue.pop(0)
+            if len(self.eventQueue) == 0:
+                self.eventQueueNotify.clear()
 
-        item = self.eventQueue.pop(0)
-
-        if len(self.eventQueue) == 0:
-            self.eventQueueNotify.clear()
-
-        self.eventQueueLock.release()
         return item
 
     def waitEvent(self, delay):
@@ -686,10 +682,9 @@
         return self.getEvent()
 
     def queue_event(self, event):
-        self.eventQueueLock.acquire()
-        self.eventQueue.append(event)
-        self.eventQueueNotify.set()
-        self.eventQueueLock.release()
+        with self.eventQueueLock:
+            self.eventQueue.append(event)
+            self.eventQueueNotify.set()
 
     def send_event(self, event):
         self.queue_event(pickle.loads(event))
@@ -698,13 +693,17 @@
         bb.utils.set_process_name("UIEventQueue")
         while True:
             try:
-                self.reader.wait()
-                event = self.reader.get()
-                self.queue_event(event)
-            except EOFError:
+                ready = self.reader.wait(0.25)
+                if ready:
+                    event = self.reader.get()
+                    self.queue_event(event)
+            except (EOFError, OSError, TypeError):
                 # Easiest way to exit is to close the file descriptor to cause an exit
                 break
+
+    def close(self):
         self.reader.close()
+        self.t.join()
 
 class ConnectionReader(object):
 
diff --git a/poky/bitbake/lib/bb/siggen.py b/poky/bitbake/lib/bb/siggen.py
index 08eca78..3f3d6df 100644
--- a/poky/bitbake/lib/bb/siggen.py
+++ b/poky/bitbake/lib/bb/siggen.py
@@ -120,6 +120,9 @@
     def save_unitaskhashes(self):
         return
 
+    def copy_unitaskhashes(self, targetdir):
+        return
+
     def set_setscene_tasks(self, setscene_tasks):
         return
 
@@ -358,6 +361,9 @@
     def save_unitaskhashes(self):
         self.unihash_cache.save(self.unitaskhashes)
 
+    def copy_unitaskhashes(self, targetdir):
+        self.unihash_cache.copyfile(targetdir)
+
     def dump_sigtask(self, fn, task, stampbase, runtime):
 
         tid = fn + ":" + task
diff --git a/poky/bitbake/lib/bb/tests/fetch.py b/poky/bitbake/lib/bb/tests/fetch.py
index 1152e89..622c46a 100644
--- a/poky/bitbake/lib/bb/tests/fetch.py
+++ b/poky/bitbake/lib/bb/tests/fetch.py
@@ -2802,3 +2802,96 @@
         fetcher.unpack(self.unpackdir)
         alt = os.path.join(self.unpackdir, 'git/.git/objects/info/alternates')
         self.assertFalse(os.path.exists(alt))
+
+
+class FetchPremirroronlyLocalTest(FetcherTest):
+
+    def setUp(self):
+        super(FetchPremirroronlyLocalTest, self).setUp()
+        self.mirrordir = os.path.join(self.tempdir, "mirrors")
+        os.mkdir(self.mirrordir)
+        self.reponame = "bitbake"
+        self.gitdir = os.path.join(self.tempdir, "git", self.reponame)
+        self.recipe_url = "git://git.fake.repo/bitbake"
+        self.d.setVar("BB_FETCH_PREMIRRORONLY", "1")
+        self.d.setVar("BB_NO_NETWORK", "1")
+        self.d.setVar("PREMIRRORS", self.recipe_url + " " + "file://{}".format(self.mirrordir) + " \n")
+
+    def make_git_repo(self):
+        self.mirrorname = "git2_git.fake.repo.bitbake.tar.gz"
+        recipeurl = "git:/git.fake.repo/bitbake"
+        os.makedirs(self.gitdir)
+        self.git("init", self.gitdir)
+        for i in range(0):
+            self.git_new_commit()
+        bb.process.run('tar -czvf {} .'.format(os.path.join(self.mirrordir, self.mirrorname)), cwd =  self.gitdir)
+
+    def git_new_commit(self):
+        import random
+        testfilename = "bibake-fetch.test"
+        os.unlink(os.path.join(self.mirrordir, self.mirrorname))
+        with open(os.path.join(self.gitdir, testfilename), "w") as testfile:
+            testfile.write("Useless random data {}".format(random.random()))
+        self.git("add {}".format(testfilename), self.gitdir)
+        self.git("commit -a -m \"This random commit {}. I'm useless.\"".format(random.random()), self.gitdir)
+        bb.process.run('tar -czvf {} .'.format(os.path.join(self.mirrordir, self.mirrorname)), cwd =  self.gitdir)
+        return self.git("rev-parse HEAD", self.gitdir).strip()
+
+    def test_mirror_commit_nonexistent(self):
+        self.make_git_repo()
+        self.d.setVar("SRCREV", "0"*40)
+        fetcher = bb.fetch.Fetch([self.recipe_url], self.d)
+        with self.assertRaises(bb.fetch2.NetworkAccess):
+            fetcher.download()
+
+    def test_mirror_commit_exists(self):
+        self.make_git_repo()
+        self.d.setVar("SRCREV", self.git_new_commit())
+        fetcher = bb.fetch.Fetch([self.recipe_url], self.d)
+        fetcher.download()
+        fetcher.unpack(self.unpackdir)
+
+    def test_mirror_tarball_nonexistent(self):
+        self.d.setVar("SRCREV", "0"*40)
+        fetcher = bb.fetch.Fetch([self.recipe_url], self.d)
+        with self.assertRaises(bb.fetch2.NetworkAccess):
+            fetcher.download()
+
+class FetchPremirroronlyNetworkTest(FetcherTest):
+
+    def setUp(self):
+        super(FetchPremirroronlyNetworkTest, self).setUp()
+        self.mirrordir = os.path.join(self.tempdir, "mirrors")
+        os.mkdir(self.mirrordir)
+        self.reponame = "fstests"
+        self.clonedir = os.path.join(self.tempdir, "git")
+        self.gitdir = os.path.join(self.tempdir, "git", "{}.git".format(self.reponame))
+        self.recipe_url = "git://git.yoctoproject.org/fstests"
+        self.d.setVar("BB_FETCH_PREMIRRORONLY", "1")
+        self.d.setVar("BB_NO_NETWORK", "0")
+        self.d.setVar("PREMIRRORS", self.recipe_url + " " + "file://{}".format(self.mirrordir) + " \n")
+
+    def make_git_repo(self):
+        import shutil
+        self.mirrorname = "git2_git.yoctoproject.org.fstests.tar.gz"
+        os.makedirs(self.clonedir)
+        self.git("clone --bare --shallow-since=\"01.01.2013\" {}".format(self.recipe_url), self.clonedir)
+        bb.process.run('tar -czvf {} .'.format(os.path.join(self.mirrordir, self.mirrorname)), cwd =  self.gitdir)
+        shutil.rmtree(self.clonedir)
+
+    @skipIfNoNetwork()
+    def test_mirror_tarball_updated(self):
+        self.make_git_repo()
+        ## Upstream commit is in the mirror
+        self.d.setVar("SRCREV", "49d65d53c2bf558ae6e9185af0f3af7b79d255ec")
+        fetcher = bb.fetch.Fetch([self.recipe_url], self.d)
+        fetcher.download()
+
+    @skipIfNoNetwork()
+    def test_mirror_tarball_outdated(self):
+        self.make_git_repo()
+        ## Upstream commit not in the mirror
+        self.d.setVar("SRCREV", "15413486df1f5a5b5af699b6f3ba5f0984e52a9f")
+        fetcher = bb.fetch.Fetch([self.recipe_url], self.d)
+        with self.assertRaises(bb.fetch2.NetworkAccess):
+            fetcher.download()