2 files changed, 14 insertions, 2 deletions

diff --git a/bitbake/bin/bitbake-diffsigs b/bitbake/bin/bitbake-diffsigs
index 5400e5b92b..4ca085f073 100755
--- a/bitbake/bin/bitbake-diffsigs
+++ b/bitbake/bin/bitbake-diffsigs
@@ -67,7 +67,9 @@ def find_compare_task(bbhandler, pn, taskname):
                 recout.append("Unable to find matching sigdata for %s with hash %s" % (key, hash2))
             else:
                 out2 = bb.siggen.compare_sigfiles(hashfiles[hash1], hashfiles[hash2], recursecb)
-                recout.extend(list('  ' + l for l in out2))
+                for change in out2:
+                    for line in change.splitlines():
+                        recout.append('  ' + line)
 
             return recout
 
diff --git a/bitbake/lib/bb/siggen.py b/bitbake/lib/bb/siggen.py
index f47af6ded8..f497fb9caf 100644
--- a/bitbake/lib/bb/siggen.py
+++ b/bitbake/lib/bb/siggen.py
@@ -5,6 +5,7 @@ import re
 import tempfile
 import pickle
 import bb.data
+import difflib
 from bb.checksum import FileChecksumCache
 
 logger = logging.getLogger('BitBake.SigGen')
@@ -462,7 +463,16 @@ def compare_sigfiles(a, b, recursecb = None):
     changed, added, removed = dict_diff(a_data['varvals'], b_data['varvals'])
     if changed:
         for dep in changed:
-            output.append("Variable %s value changed from '%s' to '%s'" % (dep, a_data['varvals'][dep], b_data['varvals'][dep]))
+            oldval = a_data['varvals'][dep]
+            newval = b_data['varvals'][dep]
+            if newval and oldval and ('\n' in oldval or '\n' in newval):
+                diff = difflib.unified_diff(oldval.splitlines(), newval.splitlines(), lineterm='')
+                # Cut off the first two lines, since we aren't interested in
+                # the old/new filename (they are blank anyway in this case)
+                difflines = list(diff)[2:]
+                output.append("Variable %s value changed:\n%s" % (dep, '\n'.join(difflines)))
+            else:
+                output.append("Variable %s value changed from '%s' to '%s'" % (dep, oldval, newval))
 
     if not 'file_checksum_values' in a_data:
          a_data['file_checksum_values'] = {}