Last I checked, test_idle passes on the stable buildbots.

But it fails on a machine without threads, such as http://buildbot.python.org/all/builders /AMD64%20Fedora%20without%20threads%203.3/builds/752/steps/test/logs/stdio
On this machine, thread-related tests are skipped: some seem expected, some not.

The chain of imports is test_pathbrowser <- PathBrowser <- ClassBrowser <- PyShell <- threading <- _thread. Since a PyShell import is required to run Idle (PyShell.main), even with just the editor, I will put the _thread import check in test_idle itself rather than sprinkling it throughout the test suite as dependencies are discovered.

(Besides the bother of the latter, the dependency could go away if PyShell only uses threading to runs user code in the same process, or delayed if it is used for other features that might not be used.)