https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81114
--- Comment #9 from simon at pushface dot org --- Created attachment 56140 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56140&action=edit C demonstrator As noted in comment 8, the C compiler doesn’t have a problem with finding a file with a combining filename when the #include directice uses a composed filename.