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diff --git a/meta/classes/reproducible_build.bbclass b/meta/classes/reproducible_build.bbclass
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+#
+# reproducible_build.bbclass
+#
+# This bbclass is mainly responsible to determine SOURCE_DATE_EPOCH on a per recipe base.
+# We need to set a recipe specific SOURCE_DATE_EPOCH in each recipe environment for various tasks.
+# One way would be to modify all recipes one-by-one to specify SOURCE_DATE_EPOCH explicitly, 
+# but that is not realistic as there are hundreds (probably thousands) of recipes in various meta-layers.
+# Therefore we do it this class. 
+# After sources are unpacked but before they are patched, we try to determine the value for SOURCE_DATE_EPOCH.
+#
+# There are 4 ways to determine SOURCE_DATE_EPOCH:
+#
+# 1. Use value from __source_date_epoch.txt file if this file exists. 
+#    This file was most likely created in the previous build by one of the following methods 2,3,4. 
+#    In principle, it could actually provided by a recipe via SRC_URI
+#
+# If the file does not exist, first try to determine the value for SOURCE_DATE_EPOCH:
+#
+# 2. If we detected a folder .git, use .git last commit date timestamp, as git does not allow checking out
+#    files and preserving their timestamps.
+#
+# 3. Use the mtime of "known" files such as NEWS, CHANGLELOG, ...
+#    This will work fine for any well kept repository distributed via tarballs.
+#
+# 4. If the above steps fail, we need to check all package source files and use the youngest file of the source tree.
+#
+# Once the value of SOURCE_DATE_EPOCH is determined, it is stored in the recipe ${WORKDIR}/source_date_epoch folder
+# in a text file "__source_date_epoch.txt'. If this file is found by other recipe task, the value is exported in
+# the SOURCE_DATE_EPOCH variable in the task environment. This is done in an anonymous python function, 
+# so SOURCE_DATE_EPOCH is guaranteed to exist for all tasks the may use it (do_configure, do_compile, do_package, ...)
+
+BUILD_REPRODUCIBLE_BINARIES ??= '1'
+inherit ${@oe.utils.ifelse(d.getVar('BUILD_REPRODUCIBLE_BINARIES') == '1', 'reproducible_build_simple', '')}
+
+SDE_DIR ="${WORKDIR}/source-date-epoch"
+SDE_FILE = "${SDE_DIR}/__source_date_epoch.txt"
+
+SSTATETASKS += "do_deploy_source_date_epoch"
+
+do_deploy_source_date_epoch () {
+    echo "Deploying SDE to ${SDE_DIR}."
+}
+
+python do_deploy_source_date_epoch_setscene () {
+    sstate_setscene(d)
+}
+
+do_deploy_source_date_epoch[dirs] = "${SDE_DIR}"
+do_deploy_source_date_epoch[sstate-plaindirs] = "${SDE_DIR}"
+addtask do_deploy_source_date_epoch_setscene
+addtask do_deploy_source_date_epoch before do_configure after do_patch
+
+def get_source_date_epoch_known_files(d, path):
+    source_date_epoch = 0
+    known_files = set(["NEWS", "ChangeLog", "Changelog", "CHANGES"])
+    for file in known_files:
+        filepath = os.path.join(path,file)
+        if os.path.isfile(filepath):
+            mtime = int(os.path.getmtime(filepath))
+            # There may be more than one "known_file" present, if so, use the youngest one
+            if mtime > source_date_epoch:
+                source_date_epoch = mtime
+    return source_date_epoch
+
+def find_git_folder(path):
+    exclude = set(["temp", "license-destdir", "patches", "recipe-sysroot-native", "recipe-sysroot", "pseudo", "build", "image", "sysroot-destdir"])
+    for root, dirs, files in os.walk(path, topdown=True):
+        dirs[:] = [d for d in dirs if d not in exclude]
+        if '.git' in dirs:
+            #bb.warn("found root:%s" % (str(root)))
+            return root
+     
+def get_source_date_epoch_git(d, path):
+    source_date_epoch = 0
+    if "git://" in d.getVar('SRC_URI'):
+        gitpath = find_git_folder(d.getVar('WORKDIR'))
+        if gitpath != None:
+            import subprocess
+            if os.path.isdir(os.path.join(gitpath,".git")):
+                try:
+                    source_date_epoch = int(subprocess.check_output(['git','log','-1','--pretty=%ct'], cwd=path))
+                    #bb.warn("JB *** gitpath:%s sde: %d" % (gitpath,source_date_epoch))
+                    bb.debug(1, "git repo path:%s sde: %d" % (gitpath,source_date_epoch))
+                except subprocess.CalledProcessError as grepexc:
+                    #bb.warn( "Expected git repository not found, (path: %s) error:%d" % (gitpath, grepexc.returncode))
+                    bb.debug(1, "Expected git repository not found, (path: %s) error:%d" % (gitpath, grepexc.returncode))
+        else:
+            bb.warn("Failed to find a git repository for path:%s" % (path))
+    return source_date_epoch
+            
+python do_create_source_date_epoch_stamp() {
+    path = d.getVar('S')
+    if not os.path.isdir(path):
+        bb.warn("Unable to determine source_date_epoch! path:%s" % path)
+        return
+
+    epochfile = d.getVar('SDE_FILE')
+    if os.path.isfile(epochfile):
+        bb.debug(1, " path: %s reusing __source_date_epoch.txt" % epochfile)
+        return
+ 
+    # Try to detect/find a git repository
+    source_date_epoch = get_source_date_epoch_git(d, path)
+    if source_date_epoch == 0:
+        source_date_epoch = get_source_date_epoch_known_files(d, path)
+    if source_date_epoch == 0:
+        # Do it the hard way: check all files and find the youngest one...
+        filename_dbg = None
+        exclude = set(["temp", "license-destdir", "patches", "recipe-sysroot-native", "recipe-sysroot", "pseudo", "build", "image", "sysroot-destdir"])
+        for root, dirs, files in os.walk(path, topdown=True):
+            files = [f for f in files if not f[0] == '.']
+            dirs[:] = [d for d in dirs if d not in exclude]
+
+            for fname in files:
+                filename = os.path.join(root, fname)
+                try:
+                    mtime = int(os.path.getmtime(filename))
+                except ValueError:
+                    mtime = 0
+                if mtime > source_date_epoch:
+                    source_date_epoch = mtime
+                    filename_dbg = filename
+
+        if filename_dbg != None:
+            bb.debug(1," SOURCE_DATE_EPOCH %d derived from: %s" % (source_date_epoch, filename_dbg))
+
+        if source_date_epoch == 0:
+            # empty folder, not a single file ...
+            # kernel source do_unpack is special cased
+            if not bb.data.inherits_class('kernel', d):
+                bb.debug(1, "Unable to determine source_date_epoch! path:%s" % path)
+
+    bb.utils.mkdirhier(d.getVar('SDE_DIR'))
+    with open(epochfile, 'w') as f:
+        f.write(str(source_date_epoch))
+}
+
+BB_HASHBASE_WHITELIST += "SOURCE_DATE_EPOCH"
+
+python () {
+    if d.getVar('BUILD_REPRODUCIBLE_BINARIES') == '1':
+        d.appendVarFlag("do_unpack", "postfuncs", " do_create_source_date_epoch_stamp")
+        epochfile = d.getVar('SDE_FILE')
+        source_date_epoch = "0"
+        if os.path.isfile(epochfile):
+            with open(epochfile, 'r') as f:
+                source_date_epoch = f.read()
+            bb.debug(1, "source_date_epoch stamp found ---> stamp %s" % source_date_epoch)
+        d.setVar('SOURCE_DATE_EPOCH', source_date_epoch)
+}