http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52887
--- Comment #5 from Daniel Richard G. <skunk at iskunk dot org> 2012-05-10 22:04:26 UTC --- (In reply to comment #3) > does adding this instantiation to libstdc++-v3/src/c++11/regex.cc help? Apologies Jonathan, I didn't see your comment before submitting my attachment. Preliminary results are that the instantiation allows the link to proceed. This was in a tree where the error had already occurred, however, so not the best test. I've started a new build, with the change in from the beginning, that should hopefully answer the question definitively by tomorrow.