https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120186
--- Comment #1 from Sam James <sjames at gcc dot gnu.org> --- (In reply to John Paul Adrian Glaubitz from comment #0) > Not sure how to save the preprocessed files in this case: There aren't any directly there, as these are unittests inside of selftest.cc. You could go through the build log and find the command which built selftest.cc.