http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54847
--- Comment #11 from Jack Howarth <howarth at nitro dot med.uc.edu> 2012-10-07 20:10:33 UTC --- The manual change applied to configure works and the build ends up with... #define _GLIBCXX_USE_NANOSLEEP 1 ...in include/x86_64-apple-darwin12.2.0/bits/c++config.h. So we should be able to fix this with... Index: libstdc++-v3/acinclude.m4 =================================================================== --- libstdc++-v3/acinclude.m4 (revision 192186) +++ libstdc++-v3/acinclude.m4 (working copy) @@ -1251,6 +1251,8 @@ AC_DEFUN([GLIBCXX_ENABLE_LIBSTDCXX_TIME] ], [#if _POSIX_TIMERS > 0 timespec tp; + #else + struct timespec tp; #endif nanosleep(&tp, 0); ], [ac_has_nanosleep=yes], [ac_has_nanosleep=no])