To reproduce:
1. Open project
2. Launch Unity with the batchmode and quit option :
-projectPath <ProjectPath> -logFile <ProjectPath /log1.txt> -batchmode -quit
3. Open 'log1.txt'
4. Notice that Xcode does not exist in UnityEditor.iOS namespace:

-----CompilerOutput:-stdout--exitcode: 1--compilationhadfailure: True--outfile: Temp/Assembly-CSharp-Editor.dll
Compilation failed: 1 error(s), 0 warnings
-----CompilerOutput:-stderr----------
Assets/Editor/XprojUpdater.cs(4,27): error CS0234: The type or namespace name `Xcode' does not exist in the namespace `UnityEditor.iOS'. Are you missing an assembly reference?
-----EndCompilerOutput---------------
- Finished compile Library/ScriptAssemblies/Assembly-CSharp-Editor.dll
Assets/Editor/XprojUpdater.cs(4,27): error CS0234: The type or namespace name `Xcode' does not exist in the namespace `UnityEditor.iOS'. Are you missing an assembly reference?

Reproduced: 2017.1.0p5, 2017.1.3p2, 2017.2.2p1, 2017.3.2f1, 2017.4.1f1
Not reproducible 2017.1.0p4, 2018.1.0b1, 2018.1.0b11, 2018.2.0b2