Hi, Using cygwin 3.6.0-0.66.gc77a5689f7bd I was indeed unable to reproduce the issue. However I'm getting a related but slightly different issue now, where a subprocess randomly (but quite reliably over the whole compilation process) fails with make -j (works fine with -j1 once again) Luckily i was able to make a really small test-case this time: Using MinGW 11.4.0 with the following test.c file: #define UNICODE #define _UNICODE #include #include int main() { int ret = _wsystem(L"x86_64-w64-mingw32-gcc -dumpversion"); if(ret != 0) printf("FOUND %d\n", ret); } compile using: x86_64_w64-mingw32-gcc ./test.c and run using: for i in $(seq 1 100) ; do ./a & done You should now be able to see at least one FOUND line among the output. This exact behaviour happens to me everytime I try to compile the OCaml compiler, where a gcc subprocess fails inexplicably. We've been getting this kind of error once in a while over the years (locally and in CI) but it was never reproducible to this point and it was usually fine if we restarted the compilation. Kind regards, ________________________________ From: Cygwin on behalf of David Allsopp via Cygwin Sent: 01 March 2024 15:26 To: Takashi Yano Cc: cygwin@cygwin.com Subject: Re: Regression: Cygwin 3.5.1 freezes when launching several mingw processes in parallel On Fri, 1 Mar 2024 at 08:03, Takashi Yano via Cygwin wrote: > Please try: cygwin 3.6.0-0.66.gc77a5689f7bd (TEST) I can confirm this fixes the issue for me, thank you! David -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple