Build host: etckeeper post-install fails (git repack: bad revision '/usr/bin/perl') #53

On the build host (tkldev), etckeeper's apt hook fails after every package operation:

E: Problem executing scripts DPkg::Post-Invoke 'if [ -x /usr/bin/etckeeper ]; then etckeeper post-install; fi'

Running etckeeper post-install by hand fails with:

fatal: bad revision '/usr/bin/perl'
fatal: failed to run repack

Seen on 2026-10-08 when attr was installed. bt-layer needs getfattr since Keel-Linux/buildtasks#18. The package installed fine, and /etc had nothing uncommitted. The /etc repo has one pack and its last commit is from 2026-10-02, so the hook may have been failing since then without anyone noticing.

Left as it is on purpose; nothing was changed on the host. To do:

• find the cause: an etckeeper hook, gc/repack config, or a stray argument;
• fix it;
• document the build host (tkldev) in the handbook beside docs/releases-host.md, which covers only the public host. That doc should list host packages bt-layer needs, such as attr and zstd.