http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55399
--- Comment #2 from Steve Ellcey <sje at gcc dot gnu.org> 2012-11-19 23:53:08 UTC --- Do you have any suggestions of where I should start? The failures are with tests that create preprocessed header file, remove the original header file, then compile a program that includes the header file. It fails to use the preprocessed header file in that case and then fails because the un-preprocessed header file no longer exists. I can make it work by specifying -ffreestanding, so does that mean that there is something in the system headers that is inhibiting the use of preprocessed headers? I am using the latest glibc and I do not see stdc-predef.h anywhere in my install or object directories though I do see it in the glibc source directory.