OMP: Error #15: Initializing libomp.so.5, but found unknown library already initialized.

[rpoyner-tri]

What happened?

Seen in https://drake-jenkins.csail.mit.edu/view/Production/job/linux-focal-clang-bazel-continuous-everything-release/745/:

Using drake_cc_googletest_main.cc

[==========] Running 9 tests from 2 test suites.
[----------] Global test environment set-up.
[----------] 8 tests from PointCloudTest
[ RUN      ] PointCloudTest.TestExpectedNumThreads
OMP: Error #15: Initializing libomp.so.5, but found unknown library already initialized.
OMP: Hint This means that multiple copies of the OpenMP runtime have been linked into the program. That is dangerous, since it can degrade performance or cause incorrect results. The best thing to do is to ensure that only a single OpenMP runtime is linked into the process, e.g. by avoiding static linking of the OpenMP runtime in any library. As an unsafe, unsupported, undocumented workaround you can set the environment variable KMP_DUPLICATE_LIB_OK=TRUE to allow the program to continue to execute, but that may cause crashes or silently produce incorrect results. For more information, please see http://openmp.llvm.org/

//perception:point_cloud_test_parallel                                   FAILED in 0.6s

Not able to reproduce locally. @jwnimmer-tri thinks we have seen this once before, but I have not found the prior occurrence.

Version

3968c1c

What operating system are you using?

Ubuntu 20.04

What installation option are you using?

compiled from source code using Bazel

Relevant log output

See above.

[rpoyner-tri]

Prior occurrence(s) slack discussion: https://app.slack.com/client/T0JNB2DS4/C0KDGF4V9/thread/C0KDGF4V9-1675280469.824469

[jwnimmer-tri]

My plan is to wait until #20251 is done and then see if this still matters.

[BetsyMcPhail]

Another occurance on 2/15: linux-focal-unprovisioned-clang-bazel-nightly-everything-release

[jwnimmer-tri]

This is pretty rare. I'll close until it becomes painful enough to necessitate mitigation.

[BetsyMcPhail]

This showed up again on 8/15 on Jammy --> https://drake-jenkins.csail.mit.edu/job/linux-jammy-clang-bazel-nightly-everything-debug/177/

[2:19:04 AM]  ==================== Test output for @@common_robotics_utilities//:hausdorff_distance_test:
[2:19:04 AM]  OMP: Error #15: Initializing libomp.so.5, but found unknown library already initialized.
[2:19:04 AM]  OMP: Hint This means that multiple copies of the OpenMP runtime have been linked into the program. That is dangerous, since it can degrade performance or cause incorrect results. The best thing to do is to ensure that only a single OpenMP runtime is linked into the process, e.g. by avoiding static linking of the OpenMP runtime in any library. As an unsafe, unsupported, undocumented workaround you can set the environment variable KMP_DUPLICATE_LIB_OK=TRUE to allow the program to continue to execute, but that may cause crashes or silently produce incorrect results. For more information, please see http://openmp.llvm.org/
[2:19:04 AM]  ================================================================================
[2:19:04 AM]  FAIL: @@common_robotics_utilities//:hausdorff_distance_test (see /media/ephemeral0/ubuntu/workspace/linux-jammy-clang-bazel-nightly-everything-debug/_bazel_ubuntu/8508526fa64f89536d67e125c67539f4/execroot/drake/bazel-out/k8-dbg/testlogs/external/common_robotics_utilities/hausdorff_distance_test/test.log)

[BetsyMcPhail]

12/13 - https://drake-jenkins.csail.mit.edu/job/linux-jammy-clang-bazel-continuous-everything-release/1172

[BetsyMcPhail]

12/19 - https://drake-jenkins.csail.mit.edu/job/linux-jammy-clang-bazel-continuous-everything-release/1194/