test stuck on 1-core-VM

[bmwiedemann]

While working on reproducible builds for openSUSE, I found that
our ck-0.7.2 package tests get stuck when building in a 1-core-VM (3-core also fails ; it starts to pass on 4-core).

Please ensure, tests do not loop forever. If a test cannot work without multiple cores, it is OK to auto-skip it.

test log:

[   62s] EB 524288
[   62s] EB 1048576
[   62s] EB 1048576
[   62s] EB 1048576
[   62s] make[2]: Leaving directory '/home/abuild/rpmbuild/BUILD/ck-0.7.2-build/ck-0.7.2/regressions/ck_backoff/validate'
[   62s]
[   62s] ----[ Testing barrier....
[   62s] make[2]: Entering directory '/home/abuild/rpmbuild/BUILD/ck-0.7.2-build/ck-0.7.2/regressions/ck_barrier/validate'
[   62s] rc=0;                                                   \
[   62s] for d in barrier_centralized barrier_combining barrier_dissemination barrier_tournament barrier_mcs ; do                                \
[   62s]        echo $d;                                        \
[   62s]        ./$d 4 1 1 || rc=1;                     \
[   62s] done;                                                   \
[   62s] exit $rc
[   62s] barrier_centralized
[   62s] Creating threads (barrier)...done
[   62s] Waiting for threads to finish correctness regression...WARNING: Could not affine thread: Invalid argument