https://bugs.gentoo.org/show_bug.cgi?id=473394
Having a look at the code more, the original bug is caused by the absense of a portage symlink in the right place, and PortageXS has no support for asking paludis about profiles.
I do need a way to add support for pms-agnostic profile detection if this is ever going to work on anything but Portage. ( Or, at very least, a configurable parameter to provide this value ).
Tests will be overhauled where possible not to abort the test suite / give better responses.