batch-file - Pre-Build command returns -1, when script returns 0

Question

I've configured Visual Studio to run a pre-build script. My pre-build script command is like this:

call $(SolutionDir)test.bat

My bat file is like this:

@echo error CS0006: hello bingo

and I get the same error when I explicitly return 0, like so

@echo error CS0006: hello bingo
exit 0

(including variations of exit, such as EXIT /b 0 etc.)

As intended Visual Studio's Error List window gets the nice error message I wished from the script and displays:

CS0006 hello bingo

in the correct format.

However, I then get another error message subsequently stating

"The command @echo error CS0006: hello bingo exits with error code -1".

Now this is an error I do not wish to get. Any ideas?