[oe] Pb compilation with BB_NUMBER_THREADS != 1

[MONDON Daniel]

I'm on a virtual Ubuntu 12.04 server, 16 cores, 8Go RAM free frequency (max = 163840MHz)

With BB_NUMBER_THREADS = '1', the entire project is successfully build in 12h30.

With BB_NUMBER_THREADS = '4' (same result with 12)

| LD_LIBRARY_PATH=/home/xxxxxxxxxxbuild/tmp-angstrom_v2012_05-eglibc/work/x86_64-linux/perl-native-5.14.2-r0/perl-5.14.2:/home/xxxxxxxxxxbuild/tmp-angstrom_v2012_05-eglib
c/sysroots/x86_64-linux/usr/bin/../lib/pseudo/lib:/home/xxxxxxxxxxbuild/tmp-angstrom_v2012_05-eglibc/sysroots/x86_64-linux/usr/bin/../lib/pseudo/lib64  ./perl -f -Ilib pod/buildtoc --
build-toc -q
|
|       Making x2p stuff
| make[1]: Entering directory `/home/xxxxxxxxxxbuild/tmp-angstrom_v2012_05-eglibc/work/x86_64-linux/perl-native-5.14.2-r0/perl-5.14.2/x2p'
|
| make[1]: Leaving directory `/home/xxxxxxxxxxbuild/tmp-angstrom_v2012_05-eglibc/work/x86_64-linux/perl-native-5.14.2-r0/perl-5.14.2/x2p'
| pod/buildtoc: no pods at pod/buildtoc line 305.
| make: *** [pod/perltoc.pod] Error 255
| ERROR: oe_runmake failed
NOTE: package perl-native-5.14.2-r0: task do_compile: Failed
NOTE: package perl-5.14.2-r6: task do_fetch: Started
NOTE: package perl-5.14.2-r6: task do_fetch: Succeeded
ERROR: Task 1239 (/home/xxxxxxxxxxsources/openembedded-core/meta/recipes-devtools/perl/perl-native_5.14.2.bb, do_compile) failed with exit code '1'
NOTE: Tasks Summary: Attempted 4055 tasks of which 4053 didn't need to be rerun and 1 failed.

Summary: 1 task failed:
  /home/xxxxxxxxxxsources/openembedded-core/meta/recipes-devtools/perl/perl-native_5.14.2.bb, do_compile
Summary: There was 1 ERROR message shown, returning a non-zero exit code.

Known problem ?
Any solution ?

Thanks
Daniel.