bug#23307: VLC does not build deterministically

bug#23307: VLC does not build deterministically

[Ludovic Courtès]

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Commit 4ef2721b52c4929aac15db4f8b39702cd37955a1 fixed an obvious
timestamp-related reproducibility issue in VLC 2.2.1, but there remains
a problem with the ‘lib/vlc/plugins/plugins.dat’ whose contents differ
across rebuilds by a few 32-bit values (see attached diffoscope output.)

The ‘plugins.dat’ file is generated by this rule in bin/Makefile.am:

--8<---------------cut here---------------start------------->8---
../modules/plugins.dat: vlc-cache-gen$(EXEEXT)
	$(AM_V_at)rm -f ../modules/plugins.dat
	$(AM_V_GEN)if test "$(build)" = "$(host)"; then \
		./vlc-cache-gen$(EXEEXT) ../modules ; \
	else \
		echo "Cross-compilation: cache generation skipped!" ; \
	fi
--8<---------------cut here---------------end--------------->8---

Ludo’.


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bug#23307: VLC does not build deterministically

[Ludovic Courtès]

ludo@gnu.org (Ludovic Courtès) skribis:

> Commit 4ef2721b52c4929aac15db4f8b39702cd37955a1 fixed an obvious
> timestamp-related reproducibility issue in VLC 2.2.1, but there remains
> a problem with the ‘lib/vlc/plugins/plugins.dat’ whose contents differ
> across rebuilds by a few 32-bit values (see attached diffoscope output.)
>
> The ‘plugins.dat’ file is generated by this rule in bin/Makefile.am:
>
> ../modules/plugins.dat: vlc-cache-gen$(EXEEXT)
> 	$(AM_V_at)rm -f ../modules/plugins.dat
> 	$(AM_V_GEN)if test "$(build)" = "$(host)"; then \
> 		./vlc-cache-gen$(EXEEXT) ../modules ; \
> 	else \
> 		echo "Cross-compilation: cache generation skipped!" ; \
> 	fi

Turned out to be simple:

  http://git.savannah.gnu.org/cgit/guix.git/commit/?id=cd76fbde6f70a6c0087f9330c266d51e334a0679

Ludo’.