Tarballs contain mtimes. They will not be reproducible if files have been generated during build time.

Known affected packages

Detection

Example debbindiff output]

Work-around

Known yet.

Solutions

--mtime

If indivdiual mtimes don't matter, then use the --mtime option:

     --mtime=DATE-OR-FILE
           set mtime for added files from DATE-OR-FILE

Adjusting mtimes

Use find, xargs, and touch to adjust file mtimes before tar is run. Example:

BUILD_DATE := $(shell dpkg-parsechangelog | sed -n -e 's/^Date: //p')
[…]
       find '$(DIR)' -depth -newermt '$(BUILD_DATE)' -print0 | \
               xargs -0r touch --no-dereference --date='$(BUILD_DATE)'
       […] tar […]