https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124238
--- Comment #13 from James K. Lowden <jklowden at gcc dot gnu.org> --- (In reply to Andreas Schwab from comment #12) > Note that the symbols the linker is complaining about are defined in both > ext11-inst.o and fs_ops.o. To clarify, the feature is documented at https://gcc.gnu.org/onlinedocs/libstdc++/manual/ext_io.html , see last bullet point. It sure looks to me like LTO is eliminating the symbol from the link in error. It looks like a COBOL FE problem because gcc/cobol/lexio.cc is the only file in gcc that uses ext/stdio_filebuf.h.
