[Bug other/50639] New: -flto=jobserver broken on large LTO build

[Bug other/50639] New: -flto=jobserver broken on large LTO build

[andi-gcc at firstfloor dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50639

             Bug #: 50639
           Summary: -flto=jobserver broken on large LTO build
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: andi-gcc@firstfloor.org


On a -j8 Linux kernel LTO build with -flto=jobserver I always end up with


make[3]: *** read jobs pipe: No such file or directory.  Stop.
make[3]: *** Waiting for unfinished jobs....
lto-wrapper: make returned 2 exit status
/usr/local/bin/ld-plugin: lto-wrapper failed

at the final link stage. The link is actually succeeding, but something
confuses jobserver

It works with -flto=8. The message comes from make.

It could be a regression, but it's hard to say because older much builds
usually ran into other problems.

[Bug other/50639] -flto=jobserver broken on large LTO build

[nix at esperi dot org.uk]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50639

Nix <nix at esperi dot org.uk> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nix at esperi dot org.uk

--- Comment #1 from Nix <nix at esperi dot org.uk> 2012-01-23 01:18:58 UTC ---
I can confirm the same symptoms while bootstrapping GCC on the head of the GCC
4.6 branch, with a bootstrap-lto profiledbootstrap, and GNU make 3.82. During
the stage3 (profilegenerate) libgcc build, the build suddenly stops with:

make[6]: *** read jobs pipe: No such file or directory.  Stop.
make[6]: *** Waiting for unfinished jobs....
lto-wrapper: make returned 2 exit status
/usr/bin/ld: lto-wrapper failed
collect2: ld returned 1 exit status
make[5]: *** [libgcc_s.so] Error 1

This failure appears consistent, so whatever it is it's not a race (or, if it
is, it's fearfully easy to hit).