https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68195
--- Comment #4 from Evgeniy Dushistov <dushistov at mail dot ru> --- Created attachment 36650 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36650&action=edit preprocessed sources I attached files created with gcc -E from main.cpp and Lib.cpp, hope this helps reproduce bug (used xz compressor to work around 1000KB restriction from bugzilla).