Creating a gentoo with devuser and some packages results in failure

[Andreas Florath]

This is very similar to #1681274 (but here for gentoo and not fedora)

Building a gentoo image with devuser and additional packages, results in:

2017-04-09 20:50:43.913236 | [dibdevel-run/dibdevel-run-gentoo] > * configure has detected that the sem_open function is broken.
2017-04-09 20:50:43.913288 | [dibdevel-run/dibdevel-run-gentoo] > * Please ensure that /dev/shm is mounted as a tmpfs with mode 1777.
2017-04-09 20:50:43.913339 | [dibdevel-run/dibdevel-run-gentoo] > * ERROR: dev-lang/python-2.7.12::gentoo failed (configure phase):
2017-04-09 20:50:43.913381 | [dibdevel-run/dibdevel-run-gentoo] > * Broken sem_open function (bug 496328)
2017-04-09 20:50:43.913410 | [dibdevel-run/dibdevel-run-gentoo] > *
2017-04-09 20:50:43.913443 | [dibdevel-run/dibdevel-run-gentoo] > * Call stack:
2017-04-09 20:50:43.913487 | [dibdevel-run/dibdevel-run-gentoo] > * ebuild.sh, line 115: Called src_configure
2017-04-09 20:50:43.913528 | [dibdevel-run/dibdevel-run-gentoo] > * environment, line 4273: Called die
2017-04-09 20:50:43.913567 | [dibdevel-run/dibdevel-run-gentoo] > * The specific snippet of code:
2017-04-09 20:50:43.913614 | [dibdevel-run/dibdevel-run-gentoo] > * die "Broken sem_open function (bug 496328)";

Build Log:
http://logs.openstack.org/66/444666/2/check/gate-dib-dsvm-functests-centos-7/f1bd538/console.html#_2017-04-09_20_50_43_913236