Fixes path issues with CMake generated projects

[mad-rain]

Hi!

Please see CocoaPods/CocoaPods#6268 for more info.

[CocoaPodsBarista]

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* Fixes path issues with CMake generated projects  
  [mad-rain](https://github.com/mad-rain)
  [#issue_number](https://github.com/CocoaPods/CocoaPods/issues/issue_number)

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[segiddins]

Can you please add a changelog entry and a test for this change? Thanks!

[dnkoutso]

@mad-rain ping here.

[mad-rain]

@dnkoutso, unfortunately I have limited time to spend on this issue and I have zero Ruby experience. Any help is appreciated!

[amorde]

@mad-rain we can help out with tests, but I (personally) had a hard time following the issue that was mentioned. It sounded like CMake generates projects in a certain directory, and settings PROJECT_DIR to something that doesn't work with CocoaPods.

Do you have an easy example that we can try to reproduce the issue?

[jothepro]

@amorde I created a small example project for you to demonstrate the issue. Hope this helps :)
@mad-rain Pls check the code to ensure were talking about the same thing!

https://github.com/jothepro/cocoapods_cmake_issue

[paulb777]

Continued in #739