diff --git a/poky/bitbake/lib/bb/fetch2/__init__.py b/poky/bitbake/lib/bb/fetch2/__init__.py
index 709372e..8fecc80 100644
--- a/poky/bitbake/lib/bb/fetch2/__init__.py
+++ b/poky/bitbake/lib/bb/fetch2/__init__.py
@@ -524,7 +524,7 @@
 def fetcher_parse_done():
     _checksum_cache.save_merge()
 
-def fetcher_compare_revisions():
+def fetcher_compare_revisions(d):
     """
     Compare the revisions in the persistant cache with current values and
     return true/false on whether they've changed.
@@ -777,7 +777,8 @@
     #
     format = d.getVar('SRCREV_FORMAT')
     if not format:
-        raise FetchError("The SRCREV_FORMAT variable must be set when multiple SCMs are used.")
+        raise FetchError("The SRCREV_FORMAT variable must be set when multiple SCMs are used.\n"\
+                         "The SCMs are:\n%s" % '\n'.join(scms))
 
     name_to_rev = {}
     seenautoinc = False
@@ -858,7 +859,10 @@
     # Disable pseudo as it may affect ssh, potentially causing it to hang.
     cmd = 'export PSEUDO_DISABLED=1; ' + cmd
 
-    logger.debug(1, "Running %s", cmd)
+    if workdir:
+        logger.debug(1, "Running '%s' in %s" % (cmd, workdir))
+    else:
+        logger.debug(1, "Running %s", cmd)
 
     success = False
     error_message = ""
@@ -894,7 +898,7 @@
     log remote network access, and error if BB_NO_NETWORK is set or the given
     URI is untrusted
     """
-    if d.getVar("BB_NO_NETWORK") == "1":
+    if bb.utils.to_boolean(d.getVar("BB_NO_NETWORK")):
         raise NetworkAccess(url, info)
     elif not trusted_network(d, url):
         raise UntrustedUrl(url, info)
@@ -1027,7 +1031,7 @@
         raise
 
     except IOError as e:
-        if e.errno in [os.errno.ESTALE]:
+        if e.errno in [errno.ESTALE]:
             logger.warning("Stale Error Observed %s." % ud.url)
             return False
         raise
@@ -1094,7 +1098,7 @@
     BB_ALLOWED_NETWORKS is set globally or for a specific recipe.
     Note: modifies SRC_URI & mirrors.
     """
-    if d.getVar('BB_NO_NETWORK') == "1":
+    if bb.utils.to_boolean(d.getVar("BB_NO_NETWORK")):
         return True
 
     pkgname = d.expand(d.getVar('PN', False))
@@ -1403,7 +1407,7 @@
         Fetch urls
         Assumes localpath was called first
         """
-        raise NoMethodError(url)
+        raise NoMethodError(urldata.url)
 
     def unpack(self, urldata, rootdir, data):
         iterate = False
@@ -1547,7 +1551,7 @@
         Check the status of a URL
         Assumes localpath was called first
         """
-        logger.info("URL %s could not be checked for status since no method exists.", url)
+        logger.info("URL %s could not be checked for status since no method exists.", urldata.url)
         return True
 
     def latest_revision(self, ud, d, name):
@@ -1555,7 +1559,7 @@
         Look in the cache for the latest revision, if not present ask the SCM.
         """
         if not hasattr(self, "_latest_revision"):
-            raise ParameterError("The fetcher for this URL does not support _latest_revision", url)
+            raise ParameterError("The fetcher for this URL does not support _latest_revision", ud.url)
 
         revs = bb.persist_data.persist('BB_URI_HEADREVS', d)
         key = self.generate_revision_key(ud, d, name)
@@ -1638,7 +1642,7 @@
             urls = self.urls
 
         network = self.d.getVar("BB_NO_NETWORK")
-        premirroronly = (self.d.getVar("BB_FETCH_PREMIRRORONLY") == "1")
+        premirroronly = bb.utils.to_boolean(self.d.getVar("BB_FETCH_PREMIRRORONLY"))
 
         for u in urls:
             ud = self.ud[u]
@@ -1716,7 +1720,7 @@
                 update_stamp(ud, self.d)
 
             except IOError as e:
-                if e.errno in [os.errno.ESTALE]:
+                if e.errno in [errno.ESTALE]:
                     logger.error("Stale Error Observed %s." % u)
                     raise ChecksumError("Stale Error Detected")
 
@@ -1786,7 +1790,7 @@
 
         for url in urls:
             if url not in self.ud:
-                self.ud[url] = FetchData(url, d)
+                self.ud[url] = FetchData(url, self.d)
             ud = self.ud[url]
             ud.setup_localpath(self.d)
 
diff --git a/poky/bitbake/lib/bb/fetch2/git.py b/poky/bitbake/lib/bb/fetch2/git.py
index 59a2ee8..8185bf4 100644
--- a/poky/bitbake/lib/bb/fetch2/git.py
+++ b/poky/bitbake/lib/bb/fetch2/git.py
@@ -199,7 +199,7 @@
             depth_default = 1
         ud.shallow_depths = collections.defaultdict(lambda: depth_default)
 
-        revs_default = d.getVar("BB_GIT_SHALLOW_REVS", True)
+        revs_default = d.getVar("BB_GIT_SHALLOW_REVS")
         ud.shallow_revs = []
         ud.branches = {}
         for pos, name in enumerate(ud.names):
@@ -318,7 +318,7 @@
     def try_premirror(self, ud, d):
         # If we don't do this, updating an existing checkout with only premirrors
         # is not possible
-        if d.getVar("BB_FETCH_PREMIRRORONLY") is not None:
+        if bb.utils.to_boolean(d.getVar("BB_FETCH_PREMIRRORONLY")):
             return True
         if os.path.exists(ud.clonedir):
             return False
@@ -522,9 +522,17 @@
     def clean(self, ud, d):
         """ clean the git directory """
 
-        bb.utils.remove(ud.localpath, True)
-        bb.utils.remove(ud.fullmirror)
-        bb.utils.remove(ud.fullmirror + ".done")
+        to_remove = [ud.localpath, ud.fullmirror, ud.fullmirror + ".done"]
+        # The localpath is a symlink to clonedir when it is cloned from a
+        # mirror, so remove both of them.
+        if os.path.islink(ud.localpath):
+            clonedir = os.path.realpath(ud.localpath)
+            to_remove.append(clonedir)
+
+        for r in to_remove:
+            if os.path.exists(r):
+                bb.note('Removing %s' % r)
+                bb.utils.remove(r, True)
 
     def supports_srcrev(self):
         return True
@@ -615,7 +623,7 @@
         """
         pupver = ('', '')
 
-        tagregex = re.compile(d.getVar('UPSTREAM_CHECK_GITTAGREGEX') or "(?P<pver>([0-9][\.|_]?)+)")
+        tagregex = re.compile(d.getVar('UPSTREAM_CHECK_GITTAGREGEX') or r"(?P<pver>([0-9][\.|_]?)+)")
         try:
             output = self._lsremote(ud, d, "refs/tags/*")
         except (bb.fetch2.FetchError, bb.fetch2.NetworkAccess) as e:
@@ -630,7 +638,7 @@
 
             tag_head = line.split("/")[-1]
             # Ignore non-released branches
-            m = re.search("(alpha|beta|rc|final)+", tag_head)
+            m = re.search(r"(alpha|beta|rc|final)+", tag_head)
             if m:
                 continue
 
diff --git a/poky/bitbake/lib/bb/fetch2/gitsm.py b/poky/bitbake/lib/bb/fetch2/gitsm.py
index b21fed2..3238913 100644
--- a/poky/bitbake/lib/bb/fetch2/gitsm.py
+++ b/poky/bitbake/lib/bb/fetch2/gitsm.py
@@ -147,6 +147,23 @@
 
         return submodules != []
 
+    def need_update(self, ud, d):
+        if Git.need_update(self, ud, d):
+            return True
+
+        try:
+            # Check for the nugget dropped by the download operation
+            known_srcrevs = runfetchcmd("%s config --get-all bitbake.srcrev" % \
+                            (ud.basecmd), d, workdir=ud.clonedir)
+
+            if ud.revisions[ud.names[0]] not in known_srcrevs.split():
+                return True
+        except bb.fetch2.FetchError:
+            # No srcrev nuggets, so this is new and needs to be updated
+            return True
+
+        return False
+
     def download(self, ud, d):
         def download_submodule(ud, url, module, modpath, d):
             url += ";bareclone=1;nobranch=1"
@@ -157,6 +174,9 @@
             try:
                 newfetch = Fetch([url], d, cache=False)
                 newfetch.download()
+                # Drop a nugget to add each of the srcrevs we've fetched (used by need_update)
+                runfetchcmd("%s config --add bitbake.srcrev %s" % \
+                            (ud.basecmd, ud.revisions[ud.names[0]]), d, workdir=ud.clonedir)
             except Exception as e:
                 logger.error('gitsm: submodule download failed: %s %s' % (type(e).__name__, str(e)))
                 raise
diff --git a/poky/bitbake/lib/bb/fetch2/hg.py b/poky/bitbake/lib/bb/fetch2/hg.py
index 936d043..5a2985e 100644
--- a/poky/bitbake/lib/bb/fetch2/hg.py
+++ b/poky/bitbake/lib/bb/fetch2/hg.py
@@ -99,7 +99,7 @@
     def try_premirror(self, ud, d):
         # If we don't do this, updating an existing checkout with only premirrors
         # is not possible
-        if d.getVar("BB_FETCH_PREMIRRORONLY") is not None:
+        if bb.utils.to_boolean(d.getVar("BB_FETCH_PREMIRRORONLY")):
             return True
         if os.path.exists(ud.moddir):
             return False
diff --git a/poky/bitbake/lib/bb/fetch2/npm.py b/poky/bitbake/lib/bb/fetch2/npm.py
index 408dfc3..65bf5a3 100644
--- a/poky/bitbake/lib/bb/fetch2/npm.py
+++ b/poky/bitbake/lib/bb/fetch2/npm.py
@@ -226,7 +226,7 @@
                         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')):
+        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))
diff --git a/poky/bitbake/lib/bb/fetch2/wget.py b/poky/bitbake/lib/bb/fetch2/wget.py
index 8f505b6..3bb3e3b 100644
--- a/poky/bitbake/lib/bb/fetch2/wget.py
+++ b/poky/bitbake/lib/bb/fetch2/wget.py
@@ -33,11 +33,14 @@
 import errno
 import bb
 import bb.progress
+import socket
+import http.client
 import urllib.request, urllib.parse, urllib.error
 from   bb.fetch2 import FetchMethod
 from   bb.fetch2 import FetchError
 from   bb.fetch2 import logger
 from   bb.fetch2 import runfetchcmd
+from   bb.fetch2 import FetchConnectionCache
 from   bb.utils import export_proxies
 from   bs4 import BeautifulSoup
 from   bs4 import SoupStrainer
@@ -132,10 +135,6 @@
         return True
 
     def checkstatus(self, fetch, ud, d, try_again=True):
-        import urllib.request, urllib.error, urllib.parse, socket, http.client
-        from urllib.response import addinfourl
-        from bb.fetch2 import FetchConnectionCache
-
         class HTTPConnectionCache(http.client.HTTPConnection):
             if fetch.connection_cache:
                 def connect(self):
@@ -168,7 +167,7 @@
                 """
                 host = req.host
                 if not host:
-                    raise urlllib2.URLError('no host given')
+                    raise urllib.error.URLError('no host given')
 
                 h = http_class(host, timeout=req.timeout) # will parse host:port
                 h.set_debuglevel(self._debuglevel)
@@ -185,7 +184,7 @@
                 # request.
 
                 # Don't close connection when connection_cache is enabled,
-                if fetch.connection_cache is None: 
+                if fetch.connection_cache is None:
                     headers["Connection"] = "close"
                 else:
                     headers["Connection"] = "Keep-Alive" # Works for HTTP/1.0
@@ -252,7 +251,7 @@
                         pass
                     closed = False
 
-                resp = addinfourl(fp_dummy(), r.msg, req.get_full_url())
+                resp = urllib.response.addinfourl(fp_dummy(), r.msg, req.get_full_url())
                 resp.code = r.status
                 resp.msg = r.reason
 
@@ -271,17 +270,16 @@
                 fp.read()
                 fp.close()
 
-                newheaders = dict((k,v) for k,v in list(req.headers.items())
+                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))
 
-            """
-            Some servers (e.g. GitHub archives, hosted on Amazon S3) return 403
-            Forbidden when they actually mean 405 Method Not Allowed.
-            """
+
+            # Some servers (e.g. GitHub archives, hosted on Amazon S3) return 403
+            # Forbidden when they actually mean 405 Method Not Allowed.
             http_error_403 = http_error_405
 
 
@@ -292,15 +290,15 @@
             """
             def redirect_request(self, req, fp, code, msg, headers, newurl):
                 newreq = urllib.request.HTTPRedirectHandler.redirect_request(self, req, fp, code, msg, headers, newurl)
-                newreq.get_method = lambda: req.get_method()
+                newreq.get_method = req.get_method
                 return newreq
         exported_proxies = export_proxies(d)
 
         handlers = [FixedHTTPRedirectHandler, HTTPMethodFallback]
-        if export_proxies:
+        if exported_proxies:
             handlers.append(urllib.request.ProxyHandler())
         handlers.append(CacheHTTPHandler())
-        # XXX: Since Python 2.7.9 ssl cert validation is enabled by default
+        # Since Python 2.7.9 ssl cert validation is enabled by default
         # see PEP-0476, this causes verification errors on some https servers
         # so disable by default.
         import ssl
@@ -319,19 +317,19 @@
                 '''Adds Basic auth to http request, pass in login:password as string'''
                 import base64
                 encodeuser = base64.b64encode(login_str.encode('utf-8')).decode("utf-8")
-                authheader =  "Basic %s" % encodeuser
+                authheader = "Basic %s" % encodeuser
                 r.add_header("Authorization", authheader)
 
-            if ud.user:
-                add_basic_auth(ud.user, r)
+            if ud.user and ud.pswd:
+                add_basic_auth(ud.user + ':' + ud.pswd, r)
 
             try:
-                import netrc, urllib.parse
+                import netrc
                 n = netrc.netrc()
                 login, unused, password = n.authenticators(urllib.parse.urlparse(uri).hostname)
                 add_basic_auth("%s:%s" % (login, password), r)
             except (TypeError, ImportError, IOError, netrc.NetrcParseError):
-                 pass
+                pass
 
             with opener.open(r) as response:
                 pass
@@ -396,18 +394,14 @@
         (oldpn, oldpv, oldsuffix) = old
         (newpn, newpv, newsuffix) = new
 
-        """
-        Check for a new suffix type that we have never heard of before
-        """
-        if (newsuffix):
+        # Check for a new suffix type that we have never heard of before
+        if newsuffix:
             m = self.suffix_regex_comp.search(newsuffix)
             if not m:
                 bb.warn("%s has a possible unknown suffix: %s" % (newpn, newsuffix))
                 return False
 
-        """
-        Not our package so ignore it
-        """
+        # Not our package so ignore it
         if oldpn != newpn:
             return False
 
@@ -473,15 +467,14 @@
 
         return ""
 
-    def _check_latest_version_by_dir(self, dirver, package, package_regex,
-            current_version, ud, d):
+    def _check_latest_version_by_dir(self, dirver, package, package_regex, current_version, ud, d):
         """
-            Scan every directory in order to get upstream version.
+        Scan every directory in order to get upstream version.
         """
         version_dir = ['', '', '']
         version = ['', '', '']
 
-        dirver_regex = re.compile("(?P<pfx>\D*)(?P<ver>(\d+[\.\-_])+(\d+))")
+        dirver_regex = re.compile(r"(?P<pfx>\D*)(?P<ver>(\d+[\.\-_])+(\d+))")
         s = dirver_regex.search(dirver)
         if s:
             version_dir[1] = s.group('ver')
@@ -541,26 +534,26 @@
                 gst-fluendo-mp3
         """
         # match most patterns which uses "-" as separator to version digits
-        pn_prefix1 = "[a-zA-Z][a-zA-Z0-9]*([-_][a-zA-Z]\w+)*\+?[-_]"
+        pn_prefix1 = r"[a-zA-Z][a-zA-Z0-9]*([-_][a-zA-Z]\w+)*\+?[-_]"
         # a loose pattern such as for unzip552.tar.gz
-        pn_prefix2 = "[a-zA-Z]+"
+        pn_prefix2 = r"[a-zA-Z]+"
         # a loose pattern such as for 80325-quicky-0.4.tar.gz
-        pn_prefix3 = "[0-9]+[-]?[a-zA-Z]+"
+        pn_prefix3 = r"[0-9]+[-]?[a-zA-Z]+"
         # Save the Package Name (pn) Regex for use later
-        pn_regex = "(%s|%s|%s)" % (pn_prefix1, pn_prefix2, pn_prefix3)
+        pn_regex = r"(%s|%s|%s)" % (pn_prefix1, pn_prefix2, pn_prefix3)
 
         # match version
-        pver_regex = "(([A-Z]*\d+[a-zA-Z]*[\.\-_]*)+)"
+        pver_regex = r"(([A-Z]*\d+[a-zA-Z]*[\.\-_]*)+)"
 
         # match arch
         parch_regex = "-source|_all_"
 
         # src.rpm extension was added only for rpm package. Can be removed if the rpm
         # packaged will always be considered as having to be manually upgraded
-        psuffix_regex = "(tar\.gz|tgz|tar\.bz2|zip|xz|tar\.lz|rpm|bz2|orig\.tar\.gz|tar\.xz|src\.tar\.gz|src\.tgz|svnr\d+\.tar\.bz2|stable\.tar\.gz|src\.rpm)"
+        psuffix_regex = r"(tar\.gz|tgz|tar\.bz2|zip|xz|tar\.lz|rpm|bz2|orig\.tar\.gz|tar\.xz|src\.tar\.gz|src\.tgz|svnr\d+\.tar\.bz2|stable\.tar\.gz|src\.rpm)"
 
         # match name, version and archive type of a package
-        package_regex_comp = re.compile("(?P<name>%s?\.?v?)(?P<pver>%s)(?P<arch>%s)?[\.-](?P<type>%s$)"
+        package_regex_comp = re.compile(r"(?P<name>%s?\.?v?)(?P<pver>%s)(?P<arch>%s)?[\.-](?P<type>%s$)"
                                                     % (pn_regex, pver_regex, parch_regex, psuffix_regex))
         self.suffix_regex_comp = re.compile(psuffix_regex)
 
@@ -572,7 +565,7 @@
             version = self._parse_path(package_regex_comp, package)
             if version:
                 package_custom_regex_comp = re.compile(
-                    "(?P<name>%s)(?P<pver>%s)(?P<arch>%s)?[\.-](?P<type>%s)" %
+                    r"(?P<name>%s)(?P<pver>%s)(?P<arch>%s)?[\.-](?P<type>%s)" %
                     (re.escape(version[0]), pver_regex, parch_regex, psuffix_regex))
             else:
                 package_custom_regex_comp = None
@@ -589,7 +582,7 @@
         current_version = ['', d.getVar('PV'), '']
 
         """possible to have no version in pkg name, such as spectrum-fw"""
-        if not re.search("\d+", package):
+        if not re.search(r"\d+", package):
             current_version[1] = re.sub('_', '.', current_version[1])
             current_version[1] = re.sub('-', '.', current_version[1])
             return (current_version[1], '')
@@ -607,13 +600,13 @@
 
             # search for version matches on folders inside the path, like:
             # "5.7" in http://download.gnome.org/sources/${PN}/5.7/${PN}-${PV}.tar.gz
-            dirver_regex = re.compile("(?P<dirver>[^/]*(\d+\.)*\d+([-_]r\d+)*)/")
+            dirver_regex = re.compile(r"(?P<dirver>[^/]*(\d+\.)*\d+([-_]r\d+)*)/")
             m = dirver_regex.search(path)
             if m:
                 pn = d.getVar('PN')
                 dirver = m.group('dirver')
 
-                dirver_pn_regex = re.compile("%s\d?" % (re.escape(pn)))
+                dirver_pn_regex = re.compile(r"%s\d?" % (re.escape(pn)))
                 if not dirver_pn_regex.search(dirver):
                     return (self._check_latest_version_by_dir(dirver,
                         package, package_regex, current_version, ud, d), '')