Hi All, I have localized the hang in t5562 (previous thread) to the invoke-with-content-length.pl script. At least on NonStop, what happens is that the perl process hangs waiting for close($out) to complete whether explicitly or implicitly (if the call is removed). The trace for the perl process shows it hung at Perl_io_close (the platform's trace anyway). My interpretation is that the reading process is still around but is no longer reading on that pipe. If any of the processes hanging around are killed, the structure unwinds. However, when some of the tests are run, git-http-backend remains running after subtest 6 and/or 8 runs even if that subtest does not hang. The presence of other git-http-backend processes seems to interfere with subsequent tests, and if you run tests individually, subtests 6,8, and 13 consistently pass. Strangely, if a bunch of print statements are added to another terminal explicitly, the test works consistently, so this is sounding a bit either like a race condition or flushes are not being handled consistently although the code appears to handle the latter case. Simply killing old git-http-backend and/or perl processes does not make a difference so the race may involve test contents, but I can't make that determination. There is no correlation with system load. That's as far as I have been able to analyze the situation at this stage. I've CC'd the author to see whether there might be some perspective that can come in here to help out. This test has broken our CI process for git on NonStop, because of the hang, so it's rather important to us to get this resolved before the official 2.21.0. Still hoping for help on this issue, Randall
