Bug#897040: fontconfig: .uuid files in font directories not removed during purge

[Laurent Bigonville]

On Tue, 23 Oct 2018 10:49:32 +0200 Andreas Beckmann <anbe at debian.org> wrote:
 > On Wed, 26 Sep 2018 19:49:31 +0200 Sven Joachim <svenjoac at gmx.de> wrote:
 > > On 2018-05-23 16:43 +0200, Laurent Bigonville wrote:
 > > That upstream bug has been fixed in commit f5dd851[1] which is included
 > > in fontconfig 2.13.1, so I think the Debian bug should be closed too.
 > > Haven't tested whether the fix works, though.
 >
 > This doesn't work, or maybe it does not get executed by the removal
 > sequence performed by piuparts.
 >
 > Removing fonts-cantarell (0.111-2) ...
 > Removing fontconfig (2.13.1-1) ...
 > Removing libfontconfig1:amd64 (2.13.1-1) ...
 > Removing fontconfig-config (2.13.1-1) ...
 > Removing fonts-dejavu-core (2.37-1) ...
 > Removing libexpat1:amd64 (2.2.6-1) ...
 > Removing libfreetype6:amd64 (2.8.1-2) ...
 > Removing libpng16-16:amd64 (1.6.34-2) ...
 > Processing triggers for libc-bin (2.27-6) ...
 >
 > 0m52.0s INFO: IGNORED PATH at 2: /usr/share/fonts/truetype/dejavu/.uuid
 > 0m52.0s INFO: IGNORED PATH at 2: /usr/share/fonts/.uuid
 > 0m52.0s INFO: IGNORED PATH at 2: /usr/share/fonts/opentype/.uuid
 > 0m52.0s INFO: IGNORED PATH at 2: /usr/share/fonts/opentype/cantarell/.uuid
 > 0m52.0s INFO: IGNORED PATH at 2: /usr/share/fonts/truetype/.uuid
 > 0m52.5s ERROR: FAIL: Package purging left files on system:
 > /usr/share/fonts/opentype/ owned by: fonts-cantarell
 > /usr/share/fonts/opentype/cantarell/ owned by: fonts-cantarell
 >
 > Tried it manually in a sid chroot, there it works if fontconfig can
 > perform its trigger processing.
 >
 > But if fontconfig has pending triggers while being removed, .uuid files
 > will stay behind.
 > Probably add a fontconfig.prerm script and in the "remove" case perform
 > that same actions as in fontconfig.configure "triggered"
 >
 > fc-cache unfortunately does not seem to have an option for "clear the
 > cache and delete all .uuid files (and do not regenerate anything)" which
 > would be the best thing to do in fontconfig.prerm remove


FTR, f5dd851 has been reverted in fontconfig, see 
https://gitlab.freedesktop.org/fontconfig/fontconfig/merge_requests/8

An other attempt to implement this is waiting at 
https://gitlab.freedesktop.org/fontconfig/fontconfig/merge_requests/10