http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52540
--- Comment #12 from Pawel Sikora <pluto at agmk dot net> 2012-03-15 15:49:09 UTC --- hmm, i see something weird. in source tree the c++config.h contains: # undef _GLIBCXX_EXTERN_TEMPLATE # define _GLIBCXX_EXTERN_TEMPLATE -1 but after make-install the c++config.h contains: # undef _GLIBCXX_EXTERN_TEMPLATE # define _GLIBCXX_EXTERN_TEMPLATE 1 -1 ^^^^