perl-5.34.0-479.fc35 fails to build in Fedora 35 if gdbm-devel-1.20-1.fc35 is installed because a gdbm test fails:
../ext/FileCache/t/02maxopen.t ....................................... ok
gdbm_firstkey: Item not found at ../../t/lib/dbmt_common.pl line 52.
Compilation failed in require at t/gdbm.t line 6.
# Tests were run but no plan was declared and done_testing() was not seen.
# Looks like your test exited with 255 just after 5.
../ext/GDBM_File/t/gdbm.t ............................................
Dubious, test returned 255 (wstat 65280, 0xff00)
All 5 subtests passed
This is probably triggered by upgrading gdbm from 1.19 to 1.20. From a GDBM changelog:
Version 1.20, 2021-06-17
* New bucket cache
The bucket cache support has been rewritten from scratch. The new
bucket cache code provides for significant speed up of search
operations.
* Change mmap prereading strategy
Pre-reading of the memory mapper regions, introduced in version 1.19
can be advantageous only when doing intensive look-ups on a read-only
database. It degrades performance otherwise, especially if doing
multiple inserts. Therefore, this version introduces a new flag
to gdbm_open: GDBM_PREREAD. When given, it enables pre-reading of
memory mapped regions.
See https://github.com/Perl/perl5/issues/18884 for details.