It hangs on ubuntu

[weidonglian]

I am running on Ubuntu 20.04. The main python process seems to hang there waiting for some signals. see my process below, I can see all the 7 tests finished correctly, I can see their log in the log folder. However, see below

0  1000  128529  119191  20   0 614472 13988 futex_ Sl+  pts/1      0:00 python ../ext/gtest-parallel/gtest_parallel.py --output_dir=. ./distr/syb-test
0  1000  128539  128529  20   0      0     0 -      Zl+  pts/1      0:02 [test] <defunct>
0  1000  128540  128529  20   0      0     0 -      Zl+  pts/1      0:03 [test] <defunct>
0  1000  128541  128529  20   0      0     0 -      Zl+  pts/1      0:04 [test] <defunct>
0  1000  128543  128529  20   0      0     0 -      Zl+  pts/1      0:04 [test] <defunct>
0  1000  128544  128529  20   0      0     0 -      Zl+  pts/1      0:00 [test] <defunct>
0  1000  128545  128529  20   0      0     0 -      Zl+  pts/1      0:02 [test] <defunct>
0  1000  128546  128529  20   0      0     0 -      Zl+  pts/1      0:00 [test] <defunct>

128529 is the main process id and those associated processes hang there.

How to debug this?

[pbos]

No idea, my Python debugging skills are really weak. For posterity, does it happen all the time or intermittently?

[weidonglian]

The repeat is stable. I have a google test executable that contains 50 tests.

1. If I run them directly without using gtest_parallel, then it works like a charm.
2. Five of them in one suite will hang if I run in gtest_parallel, even I run them sequentially using gtest_parallel. The other 45 tests just work fine with gtest_parallel. This is ubuntu.
3. All tests work well with gtest_parallel on MacOsx and Windows.

The only problem is to run five of those 50 tests on Ubuntu with gtest_parallel no matter sequentially or not. I found a workaround by accident. I create a shell script

#!/bin/bash
./distr/syb-test "$@"

instead of calling ./distr/syb-test, I call this bash script. Magically, everything works well like a charm.
I suspect it could be something wrong with Linux process signal (SIGILL, SIGABRT, SIGTERM, etc..) though I do not do anything in my google test.

This is really mysterious.