https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69188
--- Comment #26 from anthonyfk at gmail dot com --- Thank you very much for the fix! I've tried the patch as applied to gcc-6-branch with an otherwise fresh tarball of gcc 6.3.0. When compiling lapack-3.6.1 I no longer get the original bug, but I do get: lto1: internal compiler error: resolution sub id 0x7485cad21ad62861 not in object file 0x54e61b lto_resolution_read /tmp/solido-build-20170120/gcc-6.3.0/gcc/lto/lto.c:1929 0x54e61b lto_file_read /tmp/solido-build-20170120/gcc-6.3.0/gcc/lto/lto.c:2092 0x54e61b read_cgraph_and_symbols /tmp/solido-build-20170120/gcc-6.3.0/gcc/lto/lto.c:2806 0xc9045a lto_main() /tmp/solido-build-20170120/gcc-6.3.0/gcc/lto/lto.c:3310 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <http://gcc.gnu.org/bugs.html> for instructions. lto-wrapper: fatal error: /usr/local/solido/tools/20170120/bin/gfortran returned 1 exit status compilation terminated. /usr/local/solido/tools/20170120/bin/ld: error: lto-wrapper failed collect2: error: ld returned 1 exit status make[2]: *** [Makefile:129: ../xeigtsts] Error 1 I tried searching the bug tracker to see if this was fixed already but didn't have any luck. I'll try to put together a reduced test case in the next week, but it's unfortunately a busy time of year for me so that may take longer. At the very least, I can try with the latest tarball from the 6 branch easily.