[libstdc++, patch] Fix build on APFS file system

[Petr Ovtchenkov]

On Wed, 18 Oct 2017 16:51:37 +0200
FX <fxcoudert@gmail.com> wrote:

> Parallel builds of libstdc++ on APFS filesystem (with 1 ns granularity) on macOS 10.13 often fail
> (failure rate for “make -j2” to “make -j8” is about 60% from my own builds and results reported
> by others): https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81797 This is reproducible with several
> versions of GNU make.
> 
> Changing libstdc++’s makefile to mark install-headers with .NOTPARALLEL fixes the issue. We've
> carried that patch in Homebrew (https://brew.sh) for a few months now, and have had no report of
> build issues since then.
> 
> Bootstrapped and regtested on x86_64-apple-darwin17 (as well as other platforms). OK to commit?
> 
> FX
> 
> 

From supplied info not follow that problem is on gcc build side.
I can suspect that APFS has problem with direntry intensive
modification, for example.

--

  - ptr