[Bug libstdc++/81797] gcc 7.1.0 fails to build on macOS 10.13 (High Sierra):

[chrisj at rtems dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81797

--- Comment #27 from Chris Johns <chrisj at rtems dot org> ---
(In reply to Jack Howarth from comment #25)
> (In reply to Chris Johns from comment #24)
> Doesn't cross-compiles set GLIBCXX_HOSTED_FALSE such that install-data-local
> is set to install-freestanding-headers instead of install-headers in
> libstdc++-v3/include/Makefile.in? Perhaps you need...
> 
> .NOTPARALLEL: install-freestanding-headers
> 
> as well?

I tried a number of options when looking and also I thought all that was needed
was .NOTPARALLEL:. I will boot up the Mac and take look soon.

I looked over the include's Makefile.in and I am still a little confused about
the race-condition being patched with .NOTPARALLEL. I could not see one, which
is not unusual with this type of issue. The failure for me is always in a
header the massive 'ln -s' as I stated before and this is part of the 'all'
target being invoked at this point in time yet it is a C++ file being built by
some other Makefile that is seeing the file not present and when I inspect the
directory after the failure the link is present. Is the race condition or
failure somewhere else?