Bug#1039617: liblopsub: reproducible-builds: timestamps in gzip headers for changelog and manpage

[Vagrant Cascadian]

Source: liblopsub
Severity: normal
Tags: patch
User: reproducible-builds at lists.alioth.debian.org
Usertags: timestamps
X-Debbugs-Cc: reproducible-bugs at lists.alioth.debian.org

The build timestamp is included in various gzip headers:

  https://tests.reproducible-builds.org/debian/rb-pkg/trixie/amd64/diffoscope-results/liblopsub.html

  /usr/share/doc/liblopsub-dev/changelog.Debian.gz

  gzip·compressed·data,·was·"changelog.Debian",·last·modified:·Mon·May·20·01:26:32·2024,·max·compression,·from·Unix
  vs.
  gzip·compressed·data,·was·"changelog.Debian",·last·modified:·Mon·Apr·17·19:04:49·2023,·max·compression,·from·Unix

  /usr/share/man/man1/lopsubgen.1.gz

  gzip·compressed·data,·was·"lopsubgen.1",·last·modified:·Mon·May·20·01:26:29·2024,·max·compression,·from·Unix
  vs.
  gzip·compressed·data,·was·"lopsubgen.1",·last·modified:·Mon·Apr·17·19:04:45·2023,·max·compression,·from·Unix

The attached two patches (one patching the upstream Makefile, the other
patching debian/rules) fix this by passing -n to the gzip calls used to
compress changelog.Debian and the various manpages.

According to my local tests, with these two patches applied liblopsub
should build reproducibly on tests.reproducible-builds.org once it
migrates to debian/trixie! This alone does not resolve all
reproducibilitiy issues (e.g. build paths, tested in unstable and
experimental).

Thanks for maintaining liblopsub!

live well,
  vagrant
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