It appears that -Xcomp causes the relative timing of the commands to be disturbed enough to prevent the correct operation of the test. The test should not be run with -Xcomp
------------- Commit messages: - 8298993: (process) java/lang/ProcessBuilder/UnblockSignals.java fails Changes: https://git.openjdk.org/jdk/pull/13660/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13660&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8298993 Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/13660.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/13660/head:pull/13660 PR: https://git.openjdk.org/jdk/pull/13660
