https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106665
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- I didn't see this when it got reported. It is definitely a race condition. UBsan is telling you about a real bug in the program.