Reproduction steps:
1. Download and extract the attached project.
2. Edit this line to have a correct Editor and Unity project locations.

/Applications/Unity2017.3.1p4/Unity.app/Contents/MacOS/Unity -batchmode -nographics -silent-crashes -runTests -testPlatform iOS -projectPath ~/Downloads/UnityCommandLineTestIssues/ -testsResults ./iOSResults.xml -logFile ./iOSLog.log

3. Open Terminal and run this line.
- Editor will build and open the Xcode project automatically.
4. Build it through the Xcode to an iOS device.
- Editor will crash when tests will finish.
- Callstack is attached to 'callstack.txt'.

Reproduced with:
iOS
2017.3.0f1, 2017.3.1p4

Not reproducible with:
Android

Note:
Project doesn't work with 2017.2 or 2018 versions of Unity.