https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83314
--- Comment #2 from James Clarke <jrtc27 at jrtc27 dot com> --- My guess is libbacktrace/mmapio.c (perhaps mmap.c), which calls mmap with MAP_PRIVATE, and calls `error_callback (data, "mmap", errno)` on failure. That's a function pointer, which I would assume is error_callback in libgo/runtime/go-caller{,s}.c, both of which call backtrace things.