The current upstream release is 8.6.0. The package doesn't run tests.
Fixed in those commits (by Michał Górny): https://gitweb.gentoo.org/repo/gentoo.git/commit/dev-python/oslo-config?id=7d3d7ef6c018d96d70eb74e3e9ca7bec5a261de1 https://gitweb.gentoo.org/repo/gentoo.git/commit/dev-python/oslo-config?id=4662624d6067b4aa4aeafdcee06a59b93fe305fe