Dave, You checked in r150960 here: http://gcc.gnu.org/ml/gcc-cvs/2009-08/msg00642.html
This change affected ltmain.sh: http://gcc.gnu.org/viewcvs/trunk/ltmain.sh?r1=150960&r2=150959&pathrev=150960 All of those changes to sed now make sed fail miserably on any mingw host during the build: libtool: link: /c/buildbot/vista64-mingw32/mingw-x86-x86/build/build/root/i686-w64-mingw32/bin/ar rc .libs/libssp.a ssp.o gets-chk.o memcpy-chk.o memmove-chk.o mempcpy-chk.o memset-chk.o snprintf-chk.o sprintf-chk.o stpcpy-chk.o strcat-chk.o strcpy-chk.o strncat-chk.o strncpy-chk.o vsnprintf-chk.o vsprintf-chk.o libtool: link: /c/buildbot/vista64-mingw32/mingw-x86-x86/build/build/root/i686-w64-mingw32/bin/ranlib .libs/libssp.a /bin/sed: -e expression #2, char 22: Invalid content of \{\}