Very good work, Jonathan. I am starting a simple project and I have similar problem for Amstrad CPC I have fixed user.asm location in build.bat in batch file but now I get this error:
Solved! : ) The problem is the location name of AGD, AGD path "C: Amstrad AGD Framework" should be "C: AmstradAGDFramework" blank space problem. Rename directory already works ;)