[Bug libstdc++/97465] cross build gcc with vtv enabled failed. Cannot find out headers in glibc why?

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97465

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
e.g. what kind of cross build? We're not psychic.