xctestrun generation time explodes when targets have their own CONFIGURATION_BUILD_DIR

Originator:segiddins
Number:rdar://50790260 Date Originated:2019-05-14
Status:Open Resolved:
Product:Xcode Product Version:10.2
Classification:Performance Reproducible:Always
 
Summary:
This is a regression in Xcode 10, from Xcode 9.
Verified by using `sample`, the amount of time spent in xctestrun specification generation increases exponentially in number of configuration build directories (In Xcode 9.4 it increased roughly linearly).

Steps to Reproduce:
Download the attached repo, run `./build-for-testing.sh`, and observe that the `xcodebuild` invocation takes ~5 minutes to finish after the last build step has completed. (This can be verified by inspecting the xcactivitylog, which shows that compilation finishes well before `xcodebuild` returns).


Expected Results:
`xcodebuild` should finish almost immediately after compilation has finished.

Actual Results:
`xcodebuild` spends a long time generating the xctestrun file.

Version/Build:
Xcode 10.2

You can see the exponentiality by running the script at https://gist.github.com/segiddins/8c530d91f0617a0bc9bf3180e9e1759b.

Comments


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