perl-DBD-Firebird-1.18-1.fc22 fails to build in F22 sometimes due a failing test:

t/embed-80-event-ithreads.t   (Wstat: 0 Tests: 15 Failed: 0)
  Parse errors: Bad plan.  You planned 22 tests but ran 15.

Difference between last working and failing build root is:

Removed packages:
	audit-libs-2.4
	cpp-4.9.1
	gcc-4.9.1
	gcc-c++-4.9.1
	gdb-7.8
	glib2-2.42.0
	groff-base-1.22.2
	libgcc-4.9.1
	libgomp-4.9.1
	libstdc++-4.9.1
	libstdc++-devel-4.9.1
	perl-HTTP-Tiny-0.050
	perl-Pod-Perldoc-3.24
	perl-Pod-Usage-1.63
	perl-Thread-Queue-3.05
	systemd-216
	systemd-libs-216
	tzdata-2014h
Added packages:
	audit-libs-2.4.1
	cpp-4.9.2
	gcc-4.9.2
	gcc-c++-4.9.2
	gdb-7.8.1
	glib2-2.43.0
	libgcc-4.9.2
	libgomp-4.9.2
	libstdc++-4.9.2
	libstdc++-devel-4.9.2
	perl-Pod-Parser-1.62
	systemd-217
	systemd-libs-217
	tzdata-2014i

I cannot reproduce the failure, but running the test over and over reveals, the test dead-locks after some time:

$ I=0; while (prove -v -b t/embed-80-event-ithreads.t); do echo "$I"; I=$((I+1)); done
[...]
25
t/embed-80-event-ithreads.t .. 
1..22
ok 1 - Connected to the database
ok 2 - Table is 'TESTAF'
ok 3
ok 4
ok 5
ok 6
ok 7
ok 8
ok 9 - callback registered
ok 10 - thread created
ok 11 - thread joined
ok 12 - callback unregistered
ok 13
ok 14
ok 15 - create thread


This test number matches the bad-plan error, so there can be a hidden race or a bug.