Comment # 159 on bug 111481 from Michael de Lang

Thank you for making me look twice at the contents of the variable. Although
the env variable is incorrect, the quotes don't do anything to the contents of
the variable. Rather the error is in that it is not space- but comma-separated.
For posterity, this means that I will now be running with
AMD_DEBUG="nodma,nongg". 

Commenters #150 and #151 should also look into this.