- make a few trials dirs
[TMP]/first
[TMP]/second
[TMP]/third
- fetch trial dirs in order
first
['taken']
second
third
- no more trial dirs left
None
- test checksum verification
- detect wrong checksum
ok, got RuntimeError("Checksum mismatch for 'trial_test/invalid_checksum/file2' vs. 'trial_test/invalid_checksum/checksums.md5' line 2",)
- detect missing file
ok, got RuntimeError("File listed in checksums file but missing in trials dir: 'trial_test/missing_file/file2' vs. 'trial_test/missing_file/checksums.md5' line 2",)