Reproduction steps:
1. Open the attached project
2. It contains a script which will fail to compile (but will work in Editor)
3. Try to build to any platform
4. Compiler Error CS0234 is thrown in the console
5. Clear console
6. Try building one more time
7. See that only "Error building Player because scripts had compiler errors" message is thrown and no CS0234 error

This makes it difficult to navigate to a problematic script and Unity has to be restarted in order to find where the compiler error is

Regression introduced in 5.6 version