List of known Xcode issues

Feel free to add your comments to this list.

You can do it directly on GitHub, by clicking this link, just don’t forget to send it as a Pull Request ;)

Note: mainly affects UI tests.

The root cause of the issue is that Xcode / the iOS Simulator has issues in performance limited environments. This included Virtual Machines (which is how your builds are running on, MacBook Airs, Mac Minis with HDD storage, …

It can happen even if you use Apple’s Xcode Bots CI server on non SSD Mac Mini.


Related links & reports:

Possible solutions

Xcode Unit Test fails without any error, with exit code 65

This can be caused by a lot of things, Xcode or some other tool simply omits / does not present any error message.

Some possible solutions:

Segmentation fault

The error is:

clang: error: unable to execute command: Segmentation fault: 11

This is usually due to Xcode version mismatch - that you use a different Xcode on your Mac than the one you use on

The solution is simple, just make sure that you use the same Xcode version everywhere.

Issues which occur with the Xcode Command Line Tools (xcodebuild), but not with

xcodebuild hangs when a test causes EXC_BAD_ACCESS kernel exception

xcodebuild hangs when a test causes EXC_BAD_ACCESS kernel exception

Note: this can happen only on specific iOS Simulators / iOS versions too, e.g. if the app only crashes on iOS 8, but not on iOS 9

Xcode 8 - xcodebuild .. test hangs at the very end of the tests

xcodebuild .. test hangs at the end of the tests (after it printed the summary of the tests) if the output of xcodebuild .. is piped / redirected in any way. This means that xcodebuild .. test .. | xcpretty or even tee can be used to reproduce this issue.

Every/Any Xcode command hangs

This is a rare issue, caused by running a non shared Scheme.

xcodebuild can only work with shared Schemes and user schemes (auto created by xcodebuild, unlike, does not auto create user schemes, it can only work with shared schemes and already existing user schemes ( creates the user scheme when you open the project in on the specific Mac machine the first time, for schemes which are not marked as shared). If you try to run a command on a missing / non shared Scheme it usually manifests in a “scheme not found” error, but we saw projects where it resulted in xcodebuild hanging, instead of an error message.

If this is the case then any xcodebuild command will hang, even something as simple as xcodebuild -list.


Make sure that you marked the Scheme as shared, and that you actually committed & pushed it into your repository.

Build hangs

Simulator reset

As reported here, if you do a simulator reset during the build, e.g. with a pre-action Build Phase Script xcrun simctl erase all, it can cause Xcode / the Simulator to hang.


It might also not be Xcode related, but might be caused by something in your project when it runs in an Xcode Step (Xcode Test, Xcode Archive, …). For example if you have a Run Phase Script in your Xcode project, that will run during Xcode build/test/archive, and that script hangs for some reason (e.g. it waits for a user input).

Check out our guide on frequent iOS issues for more information!