According to bug #835462, build time dependencies should use "has_version -b", but this ebuild uses "has_version" for build time dependencies.
Steps to Reproduce:
1. Make sure scons is installed in the / installation and not in the /tmp/root installation.
2 emerge dev-db/mongodb --root=/tmp/root
Pre-merge error because because no suitable python-version could be found.
It can compile using the scons-installation from /.
Tested with mongodb-5.0.5-r1