https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88750
--- Comment #29 from Jürgen Reuter <juergen.reuter at desy dot de> --- -rdynamic doesn't change anything, and ld doesn't understand -export-dynamic. I am a bit confused what to do now, as we have a workaround, i.e. using -static instead of -static-libtool-libs as libtool flag. But in general, the attempt for a completely static binary (at least on MACOSX) doesn't work, so maybe we should retire that feature.
