https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61841
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Ah I see, so Samuel's change is needed to make __gthread_active_p work on Hurd. We could have changed __gthread_active_p (as we've done e.g. for Bionic) but there's no point now.