--- chromium-70.0.3538.67/build/compute_build_timestamp.py.orig	2018-11-02 16:00:34.368933077 +0200
+++ chromium-70.0.3538.67/build/compute_build_timestamp.py	2018-11-08 04:06:21.658105129 +0200
@@ -94,6 +94,14 @@
       'build_type', help='The type of build', choices=('official', 'default'))
   args = argument_parser.parse_args()
 
+  # I don't trust LASTCHANGE magic, and I definelly want something deterministic here
+  SOURCE_DATE_EPOCH = os.getenv("SOURCE_DATE_EPOCH", None)
+  if SOURCE_DATE_EPOCH is not None:
+    print SOURCE_DATE_EPOCH
+    return 0
+  else:
+    raise RuntimeError("SOURCE_DATE_EPOCH not set")
+
   # The mtime of the revision in build/util/LASTCHANGE is stored in a file
   # next to it. Read it, to get a deterministic time close to "now".
   # That date is then modified as described at the top of the file so that