del os.environ[]
os.unsetenv
Simon discovered that `os.unsetenv()` will not remove the env from os.environ so this commit fixes this. Thanks for figuring this out!
When constructing a minimal environment for osbuild the exported dirs lacked "schemas" so the test_exports.py test failed on RHEL8. This commit adds it (and also "assemblers" for good measure). With that the test will pass.