Use async execution for xcodebuild commands

[priitlatt]

Description

Sometimes Flutter never receives the output of xcodebuild -list and xcodebuild -showBuildSettings commands while they have actually been completed underneath (no alive processes for xcodebuild are present). For unknown reasons, the issue does not reproduce when the commands are invoked with runCheckedAsync instead of runCheckedSync.

Related Issues

#28415

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[jonahwilliams]

I'm ready to LGTM once the CLA is signed and the test is fixed

[jonahwilliams]

@priitlatt are you able to continue working on it or should we continue ourselves?

[priitlatt]

@jonahwilliams We were observing how this fix behaves in the production over the weekend and yesterday. At first it was very promising, but now it seems that it still occasionally gets stuck on /usr/bin/xcodebuild -project /paht/to/Runner.xcodeproj -target Runner -showBuildSettings.

Also, making XcodeProjectInterpreter#getBuildSettings async has proven to be a bit more involved than I initially thought it would be (this also causes the tests and some functionality to break). And on top of the complications, it doesn't even give the desired result.

But async version of XcodeProjectInterpreter#getInfo seems to solve at least half of the problem for now. So I'll revert changes related to getBuildSettings and perhaps we could move on with getInfo being async for now?

[jonahwilliams]

That sounds reasonable to me

[jonahwilliams]

cc @priitlatt what are your plans with this CL? If this improves the situation I would prefer to land it and continue addressing other forms of flakiness separately

[priitlatt]

@jonahwilliams Last I checked the Flutter build was failing and hence the delays, sorry about that. I'm good to go on with this and continue with showBuildSettings getting stuck separately. Also, I've signed the CLA in the meantime.

[jonahwilliams]

LGTM,

Thank you for the contribution!

[priitlatt]

I signed it!

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[jonsamwell]

Is this in the stable branch yet?