Bug Files generated by test without cleanup.

Hi,
I'm having an issue, where testing an editor internal workflow for assets. I create an asset, perform an copy on that (both using the AssetDatabase calls) and assert for some statuses within the copy. So far, so good.
Now, each time I run the test I get the warning "Files generated by test without cleanup." and a list of the created files, although they are wiped with the corresponding directory in TearDown. I tried the following things:
* Running SetUp and TearDown in their Unity versions with yielding after the deletion
* Running the test as UnityTest with yielding after each operation
* Deleting the directory in the test itself instead of TearDown
In any case I get the message, although everytime the directory is removed for good.



Another thing I encounter is, as this test is part of a custom package, it opens an error window, stating, that a move operation can't be done, because the target directory can't be found. This occurs not with the test itself, but with the next test running - where the target directory isn't available by design.



Are these expected behaviours? Seems like a bug to me at the moment. How can I work around these issues, I ran out of ideas...