[PlistHelper] Fall back to XML project output when Xcode initializati…

[segiddins]

…on fails.

Closes CocoaPods/CocoaPods#3723.

[neonichu]

Looks good in general, but it seems to only work with Xcode 7, because IDEInitialize() returns 0 on previous versions, even when it is working.

[neonichu]

BTW, this makes me think that it would be nice to have an env variable to completely disable loading of Xcode frameworks, so that users have an immediate workaround in case of breakage like this. I expected this to be a rather stable interface, but it evidently isn't.

[alloy]

Another option would be to have a list of supported Xcode versions. The pro is that the user doesn’t need to know of an option that’s likely to be hard to find, the con is that it requires a CP update for new Xcode versions to work.

[alloy]

Or you could do both and have the env variable also be available to enable the functionality when running on an unsupported Xcode version.

[neonichu]

@alloy that sounds like a better idea - finally we can have those compatibility UUIDs inside CP :)

[alloy]

@neonichu lol, yah :D

[segiddins]

@neonichu want to take this over, then?

[neonichu]

@segiddins I would do the version detection as a separate PR - if you want, I can also finish this one.

[segiddins]

Yes please :)

[ddunbar]

If there is going to be an option for this, it might also be nice to have a way to not suppress stderr when calling IDEInitialize(), so it is more obvious what the exact failure is without having to modify the Xcodeproj code.

[segiddins]

@ddunbar maybe, but i'd honestly prefer just to print it out when IDEInitialize fails

[neonichu]

This should be good to merge now. It retains functionality for Xcode versions 7 beta 1 and earlier, while not breaking on 7 beta 2. However, it does not enable ASCII plist writing for 7 beta 2, opened #278 for tracking that.

[segiddins]

@neonichu add yourself :)

[segiddins]

👍