Sorry that I'm just now seeing this.
I'm not entirely sure what the problem is, but since it is saying that it can't find rgbasm, you must have put the exe's in the wrong directory.
Make sure the rgbds exe's are immediately in usr/local/bin/ (not in any subdirectories)
Also, is there is reason you wanted to put the repositories in your usr/ folder instead of your home/ folder? I don't know but that may cause an issue.