test-concurrency.py sometimes fails

[jlebon]

See e.g. https://github.com/ostreedev/ostree/pull/2025#issuecomment-600917509:

ERROR: tests/test-concurrency.py
================================
n_committers 4 n_pruners 0
Creating tree tree0
Creating tree tree1
PID 30315 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 30316 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 30317 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 30318 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 30316 exited OK
PID 30318 exited OK
PID 30317 exited OK
PID 30315 exited OK
n_committers 6 n_pruners 3
Creating tree tree0
Creating tree tree1
Creating tree tree2
PID 30321 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 30322 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 30323 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 30324 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 30325 ostree --repo=repo commit --fsync=0 -b tree2 --tree=dir=tree2
PID 30326 ostree --repo=repo commit --fsync=0 -b tree2 --tree=dir=tree2
error: opendir(staging-89ed2f5d-09e9-4dc1-8360-9d7011bc2edd-anBXJW): No such file or directory
PID 30327: ostree --repo=repo prune --refs-only
PID 30328: ostree --repo=repo prune --refs-only
PID 30329: ostree --repo=repo prune --refs-only
process 30322 exited with code 1
PID 30326 exited OK
PID 30324 exited OK
PID 30321 exited OK
PID 30323 exited OK
PID 30325 exited OK
PID 30328 exited OK
PID 30327 exited OK
PID 30329 exited OK
A child process exited abnormally
1..2
014ccd06e67eacefc6a965c01a3fe3aa953cbac93cd17ab49b7cc35325b9e8b9
67eddf38725595bf7a23c692101b6edded083c8fbc5b099ce7be5afa6f56f90c
00867bcf06c15f34b3b1ce4d62eeb13747ec470c1b52bf74f5834475fa8875d9
0fbf3241a95691c836497e5c1ae0422d67fe9e71ba8fade043c64c58970a5b0d
ok no concurrent prunes
PASS: tests/test-concurrency.py 1 no concurrent prunes
d62b8c33421f8dadd6844646cb46e7f7bf8e9dfe79db01c6829ac282fa8d3a3a
83798fcef5f1893b7848103e039021de22eaeb8615cb05e9bfa3b4b16352605a
10461655e44945cd0c923c6451de43c5cf0ad0ef11f62f5c24aabb7e9a6a1485
7a566b367f6a250f2e1433e42ad4f84120b2d6ce87856f9f3f7bddacc690689f
Total objects: 72
No unreachable objects
fd51a8b23108e97ec7d57dea2a13b9ada796e0998b1acd364b94e900aaf4d80b
Total objects: 73
No unreachable objects
Total objects: 73
No unreachable objects
ERROR: tests/test-concurrency.py - too few tests run (expected 2, got 1)
ERROR: tests/test-concurrency.py - exited with status 1

We've seen it in a few other PRs as well, though it only seems to happen on Travis CI.

[lucab]

I think I've hit this on GH (Tests / Debian Stable with curl, sign-ed25519 and no gpgme in https://github.com/ostreedev/ostree/pull/2421) with a slightly different output (a refcount assertion):

ERROR: tests/test-concurrency.py
================================

n_committers 4 n_pruners 0
Creating tree tree0
Creating tree tree1
PID 102546 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 102547 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 102548 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 102549 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 102548 exited OK
PID 102547 exited OK
PID 102549 exited OK
PID 102546 exited OK
n_committers 6 n_pruners 3
Creating tree tree0
Creating tree tree1
Creating tree tree2
PID 102550 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 102551 ostree --repo=repo commit --fsync=0 -b tree0 --tree=dir=tree0
PID 102552 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 102553 ostree --repo=repo commit --fsync=0 -b tree1 --tree=dir=tree1
PID 102554 ostree --repo=repo commit --fsync=0 -b tree2 --tree=dir=tree2
PID 102555 ostree --repo=repo commit --fsync=0 -b tree2 --tree=dir=tree2
PID 102556: ostree --repo=repo prune --refs-only

(ostree commit:102553): GLib-GObject-CRITICAL **: 12:46:01.577: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
PID 102557: ostree --repo=repo prune --refs-only
PID 102558: ostree --repo=repo prune --refs-only
PID 102550 exited OK
PID 102552 exited OK
PID 102554 exited OK
process 102553 exited with code -5
PID 102551 exited OK
PID 102555 exited OK
PID 102558 exited OK
PID 102556 exited OK
PID 102557 exited OK
A child process exited abnormally