[oe] nspr-4.7.1: race condition causing occasional build failure

[Graham Gower]

The failure looks like this:

make[3]: Entering directory `/mnt/oe/tmp/work/mipsel-oe-linux/nspr-4.7.1-r1/nspr-4.7.1/mozilla/nsprpub/pr/include/md'
../../../config/./nsinstall -R -m 444 ./_aix32.cfg ./_aix64.cfg ./_beos.cfg ./_bsdi.cfg ./_darwin.cfg ./_dgux.cfg ./_freebsd.cfg ./_hpux32.cfg ./_hpux64.cfg ./_irix32.cfg ./_irix64.cfg ./_linux.cfg ./_ncr.cfg ./_nec.cfg ./_netbsd.cfg ./_nextstep.cfg ./_nto.cfg ./_openbsd.cfg ./_openvms.cfg ./_os2.cfg ./_osf1.cfg ./_qnx.cfg ./_reliantunix.cfg ./_riscos.cfg ./_scoos.cfg ./_solaris.cfg ./_sony.cfg ./_sunos4.cfg ./_unixware.cfg ./_unixware7.cfg ./_win16.cfg ./_win95.cfg ./_winnt.cfg ../../../dist/include/nspr/md
../../../config/./nsinstall: ../../../config/./nsinstall: cannot execute binary file
make[3]: *** [export] Error 126


do_compile_prepend() contains the following line:
cp ${STAGING_BINDIR_NATIVE}/${P}/nsinstall config/nsinstall
Which copies the nsinstall program built by nspr-tools-native. However,
in the case of the failure, nspr chooses to build a version of nsinstall
for the target.

I'm having trouble reproducing this, but I can see that I am not alone
in experiencing this bug.
http://tinderbox.openembedded.net/packages/764121/

Any help with determining what causes this race would be appreciated. It has
the follow on effect of causing various other packages to fail in difficult
to diagnose ways.

-Graham