"file is not a core dump" error with zlib compression

[paper42]

I sometimes get a core dump that can not be read using corectl. It seems to happen only with gnome-maps and only when I have zlib compression enabled. I can read other core dumps fine. Disabling zlib compression and triggering the segfault again fixes this issue.

%: corectl backtrace 84
2021-04-02T17:28:53.158 [error] corectl.d:232:backtraceCore Failed to get backtrace via gdb "/tmp/gnome-maps-11-20018-1000-1000-20210402T161043ba9ba4e5-ff08-57f3-967f-ff53713086c7.gz" is not a core dump: file format not recognized
No stack.

%: file /var/lib/corecollector/gnome-maps-11-20018-1000-1000-20210402T161043ba9ba4e5-ff08-57f3-967f-ff53713086c7.gz
/var/lib/corecollector/gnome-maps-11-20018-1000-1000-20210402T161043ba9ba4e5-ff08-57f3-967f-ff53713086c7.gz: zlib compressed data