Ios cloud build fails, due to compile error before xcode, cannot find a .cs file which although exists

I am trying to build my project for ios using Unity Cloud build. My cloud build worked successfully for my earlier projects. This time I imported a common package "Toony Colors Pro". Its script files have another assembly definition file. The editor scripts belonging to the package gives errors (I included as a screenshot, cannot find MaterialLayer.cs) which is indeed there.

I compile for ios in my local machine without any error and produce an xcode project. I use Unit Cloud build with git and it is linked to a bitbucket repository. Another hint, when I clone the project from sourcetree to another location in my pc, some of my .cs files cannot be found by the compiler (?)

What can be the problem?

[1]: /storage/temp/180073-butthefileexists.png