[Bug c++/123797] Header Unit Not Found In Preprocessed File

[kongmingd234 at proton dot me]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123797

--- Comment #2 from kongmingd234 <kongmingd234 at proton dot me> ---
It could be because I do not have the latest build of GCC from trunk. Or it
could be because your test case is different from mine. I should have attached
a file containing the code. Is it not there?

It should just be.
g++ -fmodules -fmodule-mapper=mapper.txt

with -x c++-header for the headers.

Come to think of it, I may not have added the module mapper for the headers? I
will try again and get back to you.