On Wed, Dec 22, 2021 at 5:07 PM Alessandro Baretta via Gcc <gcc@gcc.gnu.org> wrote: > > Hello GCC hackers, and thank you very much for your precious work here. > > I've been observing somewhat random GCC segfaults in my C++ 20 > codebase for a while. By "random" I mean that if I rerun the cmake > build after a failure, 75% out of the time it will succeed, and it > might fail again the next time I try running the build. I have every > reason to believe that the issue is not with my code because: > 1) At the second (or more rarely third) attempt at running the build, > it succeeds. > 2) Clang does not segfault on the same codebase, and indeed produces > correct code.
Maybe https://gcc.gnu.org/PR99831 Which was fixed in GCC 10.4 but was broken in GCC 10.2.x. This is a garbage collector related Internal compiler error which can seem to randomly appear and disappear even. Thanks, Andrew Pinski > > The codebase is fairly large and heavily templatized, so I know that > the the compiler allocates a seemingly inordinate amount of memory > (using top, I've seen it reach a RES size of 1.6GB and a VIRT size of > 4GB), so I initially attributed the segfaults to lack of enough memory > on my computer (16GB, with chrome running...). Now I turned on swap > (32GB), and I see that even when gcc is running, there is plenty of > available memory, so this is not a plausible cause. > > The possibility of a hardware glitch in my system also does not hold > much water, as neither clang nor any other piece of software seems to > exhibit any instability. > > It'd be great if I could get some guidance on how to investigate this > issue further. If it were of value to the developers, I'd be happy to > file a bug report, but given the randomness of the issue, I doubt that > they'd be able to reproduce the problem even with a preprocessed file. > What then is my path forward? > > Here's some information that might be relevant: > > $ cat /etc/debian_version > 11.1 > $ gcc --version > gcc (Debian 10.2.1-6) 10.2.1 20210110 > Copyright (C) 2020 Free Software Foundation, Inc. > This is free software; see the source for copying conditions. There is NO > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. > > > Thanks for any help! > > -- > Alex Baretta > t: 650-383-0227
