In FileSystemContractBaseTest::tearDown() method, it cleans up the path("/test") directory, which will be qualified as /test (against root instead of working directory because it's absolute):
But in the test, it uses path("test") sometimes, which will be made qualified against the working directory (e.g. /user/bob/test).
This makes some tests fail intermittently, e.g. ITestS3AFileSystemContract. Also see the discussion in