http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54206
--- Comment #5 from Andi Kleen <andi-gcc at firstfloor dot org> 2012-10-04 18:50:52 UTC --- This is the configure snippet glibc is using for this. Someone with better autoconf-fu than me could add it if test "`cd $srcdir; /bin/pwd`" = "`/bin/pwd`"; then AC_MSG_ERROR([you must configure in a separate build directory]) fi
