[Bug bootstrap/50047] New: [4.7 Regression] Revision 177670 failed to bootstrap

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50047

             Bug #: 50047
           Summary: [4.7 Regression] Revision 177670 failed to bootstrap
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hjl.tools@gmail.com
                CC: ro@gcc.gnu.org


Revision 177670:

http://gcc.gnu.org/ml/gcc-cvs/2011-08/msg00684.html

breaks bootstrap with "make -j12" on a 24 core Linux/x86-64:

http://gcc.gnu.org/ml/gcc-regression/2011-08/msg00179.html

rm -f ../../.././gcc/include/unwind.h
cp unwind.h ../../.././gcc/include/unwind.h
rm -f ../.././gcc/include/unwind.h
chmod a+r ../../.././gcc/include/unwind.h
cp unwind.h ../.././gcc/include/unwind.h
chmod: cannot access `../../.././gcc/include/unwind.h': No such file
or directory
make[8]: *** [install-unwind_h] Error 1
make[8]: *** Waiting for unfinished jobs....
chmod a+r ../.././gcc/include/unwind.h

We have a race condition here.