GROMACS

In gmx_set_thread_affinity (src/gromacs/mdrunutility/threadaffinity.cpp, line 425):

    /* If the tMPI thread affinity setting is not supported encourage the user
     * to report it as it's either a bug or an exotic platform which we might
     * want to support. */
    if (!affinityAccess->isThreadAffinitySupported())
    {
        /* we know Mac OS does not support setting thread affinity, so there's
           no point in warning the user in that case. In any other case
           the user might be able to do something about it. */
#if !defined(__APPLE__)
        GMX_LOG(mdlog.warning)
                .asParagraph()
                .appendText("NOTE: Cannot set thread affinities on the current platform.");
#endif /* __APPLE__ */
        return;
    }

The comment ("Mac OS does not support setting thread affinity") does not seem to be correct (because mine does - maybe on earlier version?). This just suppresses a log output, so it's not a harmful bug, but we should revisit that comment.