https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66303
--- Comment #9 from Dominik Vogt <vogt at linux dot vnet.ibm.com> --- The problem is reproduceable with the makecontext C testcases in Glibc (with some manual intervention). So, this isn't a Go related problem. Our analysis so far seems to indicate that it's a bug in the s390x specific code of Glibc or maybe the s390x unwinding code in libgcc (less likely). We'll take care of the problem.