debian/bin/genorig.py: Make orig tarballs reproducible

debian/bin/genorig.py

@@ -8,6 +8,7 @@ import os.path
 import re
 import shutil
 import subprocess
+import time
 
 from debian_linux.debian import Changelog, VersionLinux
 
@@ -79,8 +80,19 @@ class Main(object):
                 self.upstream_extract(self.input_files[0])
             if len(self.input_files) > 1:
                 self.upstream_patch(self.input_files[1])
+
+            # generate() will change file mtimes.  Capture the
+            # original release time so we can apply it to the final
+            # tarball.  Note this doesn't work in case we apply an
+            # upstream patch, as that doesn't carry a release time.
+            orig_date = time.strftime(
+                "%a, %d %b %Y %H:%M:%S +0000",
+                time.gmtime(
+                    os.stat(os.path.join(self.dir, 'temp/Makefile'))
+                    .st_mtime))
+
             self.generate()
-            self.tar()
+            self.tar(orig_date)
         finally:
             shutil.rmtree(self.dir)
 
@@ -170,7 +182,7 @@ class Main(object):
                         os.makedirs(d)
                     shutil.copyfile(temp_j, orig_j)
 
-    def tar(self):
+    def tar(self, orig_date):
         out = os.path.join("../orig", self.orig_tar)
         try:
             os.mkdir("../orig")
@@ -182,9 +194,12 @@ class Main(object):
         except OSError:
             pass
         self.log("Generate tarball %s\n" % out)
-        cmdline = ['tar -caf', out, '-C', self.dir, self.orig]
+        cmdline = '''(cd '%s' && find '%s' -print0) |
+                     LC_ALL=C sort -z |
+                     tar -C '%s' --no-recursion --null -T - --mtime '%s' -caf '%s'
+                  ''' % (self.dir, self.orig, self.dir, orig_date, out)
         try:
-            if os.spawnv(os.P_WAIT, '/bin/sh', ['sh', '-c', ' '.join(cmdline)]):
+            if os.spawnv(os.P_WAIT, '/bin/sh', ['sh', '-c', cmdline]):
                 raise RuntimeError("Can't patch source")
             os.chmod(out, 0o644)
         except:

debian/changelog

@@ -5,6 +5,7 @@ linux-tools (4.2-1) UNRELEASED; urgency=medium
   [ Ben Hutchings ]
   * debian/bin,debian/control,debian/lib/python,debian/rules: Use Python 3
     - debian/lib/python: Sync with linux package
+  * debian/bin/genorig.py: Make orig tarballs reproducible
 
  -- Ben Hutchings <ben@decadent.org.uk>  Fri, 25 Sep 2015 18:42:20 +0100