https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61294
--- Comment #3 from Orion Poplawski <orion at cora dot nwra.com> --- Hmm, now all of a sudden I don't seem to be able to reproduce this. Thanks for your comments though. I play around if it re-appears. The problem was compounded by the use of -Wl,--fatal-warnings so it was preventing linkage.