https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93293
David Malcolm <dmalcolm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution|--- |FIXED --- Comment #5 from David Malcolm <dmalcolm at gcc dot gnu.org> --- Thanks. The consensus on the mailing list re my patch seemed to be that people should just update graphviz, rather than trying to detect this. I'm going to close this out then.