swift-version.sh hanging on Spotlight call

[larkost]

There have been a couple of jobs recently that have failed with timeouts (35 minutes in this case), and the message No version of Xcode found that supports Swift 2.2 in their logs (version of Swift does change). The line that is causing the problem is:
mdfind "kMDItemCFBundleIdentifier == 'com.apple.dt.Xcode'"
... and that will hang when you run it manually in an VM that gets into this state. There is no real reason that this situation occurs, and nothing obvious in the log about what is going on. In one case I was able to recover by re-indexing the /Applications folder, but in other cases a reboot has been required.

In the latter case all calls to mdfind or mdimporthung the same way, and calls to mdutil reported a communications error and then told me that

The most straightforward way of handling this is to first use a glob to find Xcode versions by name in /Applications, and then if what we are looking for is not there, then fall-back to Spotlight. In the case of CI, then we are always putting them there, and the fallback will work for other users if they choose to put versions elsewhere.

[larkost]

Fixed in 942fd88.