Bug#935678: cmus FTBFS on armel, mipsel, m68k, powerpc, sh4: undefined reference to `__atomic_fetch_add_8'

[Helmut Grohne <helmut@subdivi.de>]

Source: cmus
Version: 2.8.0-1
Severity: serious
Tags: ftbfs

cmus fails to build from source on armel, mipsel, m68k, powerpc, sh4
with the same error. Final linking fails to find __atomic_fetch_add_8:

|    gcc -Wl,-z,relro -Wl,-z,now -Wl,--as-needed  -o cmus ape.o browser.o buffer.o cache.o channelmap.o cmdline.o cmus.o command_mode.o comment.o convert.lo cue.o cue_utils.o debug.o discid.o editable.o expr.o filters.o format_print.o gbuf.o glob.o help.o history.o http.o id3.o input.o job.o keys.o keyval.o lib.o load_dir.o locking.o mergesort.o misc.o options.o output.o pcm.o player.o play_queue.o pl.o rbtree.o read_wrapper.o search_mode.o search.o server.o spawn.o tabexp_file.o tabexp.o track_info.o track.o tree.o uchar.o u_collate.o ui_curses.o window.o worker.o xstrjoin.o file.o path.o prog.o xmalloc.o -lpthread -lncursesw -ltinfo  -ldl -Wl,--export-dynamic -ldiscid -lm
| /usr/bin/ld: track_info.o: in function `track_info_new':
| ./track_info.c:47: undefined reference to `__atomic_fetch_add_8'
| collect2: error: ld returned 1 exit status
| make[2]: *** [Makefile:52: cmus] Error 1
| make[2]: Leaving directory '/<<PKGBUILDDIR>>'
| dh_auto_build: make -j4 V=2 returned exit code 2
| make[1]: *** [debian/rules:32: override_dh_auto_build] Error 255
| make[1]: Leaving directory '/<<PKGBUILDDIR>>'
| make: *** [debian/rules:21: build-arch] Error 2

Given that it previously built on armel and mipsel, this bug is severity
serious.

Helmut