https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88081
--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> --- I see the bug as old one: 4.9.4 (d3191480f376c780)(03 Aug 2016 05:07): [took: 1.910s] result: FAILED (1) 2.ii:9:7: warning: type of ‘_ZTVN10__cxxabiv117__class_type_infoE’ does not match original declaration class __class_type_info : a {}; ^ 1.ii:10:7: note: previously declared here class __class_type_info : a {}; ^ /usr/bin/ld: /usr/lib/../lib64/crt1.o: in function `_start': /home/abuild/rpmbuild/BUILD/glibc-2.27/csu/../sysdeps/x86_64/start.S:104: undefined reference to `main' collect2: error: ld returned 1 exit status 5.1.0 (d5ad84b309d0d97d)(22 Apr 2015 08:43): [took: 2.113s] result: FAILED (1) lto1: internal compiler error: in lto_varpool_replace_node, at lto/lto-symtab.c:143 Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. lto-wrapper: fatal error: g++ returned 1 exit status compilation terminated. /usr/bin/ld: error: lto-wrapper failed collect2: error: ld returned 1 exit status What do you want to bisect precisely Honza?