On 18/10/17 18:40 -0400, Hans-Peter Nilsson wrote:
On Wed, 18 Oct 2017, FX 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?
Maybe moot now, but .NOTPARALLEL doesn't work the way you imply
in the patch. From TFM of GNU Make 3.81 and 4: "Any
prerequisites on this target are ignored."
To wit, it seems you'd get the effect, but for *every target* in
this Makefile. (If I were you and the patch is still proposed,
I'd remove the unused target and add a comment on the intent.)
Assuming the documentation and my reading is correct.
I think it is.
