[Bug libstdc++/64161] [5 Regression] bootstrap error: condition_variable.cc:134:7: error: 'atexit' is not a member of 'std'

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64161

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
It looks like it includes stdlib.h but not the C++ wrapper, cstdlib

I'm going to commit a patch to include cstdlib as that's correct anyway, I hope
that will fix it.