Non-deterministic failure in test/AutolinkExtract


Hi all,

I occasionally see a failure in test/AutolinkExtract tests in my Ubuntu
16.04 builds.
It happens about 1 in 10 times. The failing test case is
test/AutolinkExtract/import.swift OR

You can reproduce the issue by running this command *several times*:

$ utils/run-test --build=skip --build-dir ../build/Ninja-ReleaseAssert
test/AutolinkExtract/import.swift test/AutolinkExtract/import_archive.swift



Exit Code: 254

Command Output (stderr):
clang-4.0: error: unable to execute command: Bus error (core dumped)
clang-4.0: error: linker command failed due to signal (use -v to see
<unknown>:0: error: link command failed with exit code 254 (use -v to see


It seems, running each tests independently never fails.
Maybe, file locking problem?