Description of problem:
Run createrepo_c --xz --deltas /var/tmp/local_repo

Version-Release number of selected component:
createrepo_c-0.15.5-1.fc32

Additional info:
reporter:       libreport-2.11.3
backtrace_rating: 4
cmdline:        createrepo --xz --deltas /var/tmp/local_repo/
crash_function: g_mutex_unlock
executable:     /usr/bin/createrepo_c
journald_cursor: s=0a60c0fc72ce4c1da58f325e8a0cf008;i=1d758;b=415200eb183042e798efddcb52707dd6;m=152bbe6c5;t=59d48201be35d;x=90c80973f9f5a37
kernel:         5.5.0-0.rc6.git3.1.fc32.x86_64
rootdir:        /
runlevel:       N 5
type:           CCpp
uid:            0

Truncated backtrace:
Thread no. 1 (4 frames)
 #0 g_mutex_unlock at ../glib/gthread-posix.c:1477
 #1 g_cond_wait at ../glib/gthread-posix.c:1526
 #2 g_thread_pool_start_thread at ../glib/gthreadpool.c:488
 #3 g_thread_pool_push at ../glib/gthreadpool.c:688