I'm not yet convinced of the wisdom of referring to an exact commit here, because it means every time `spotify-make` is updated, this file also needs to be updated, which could pollute the history a bit.  I guess it's a trade-off between stability and aggressive adoption - is a change to `spotify-make` more likely to improve this installer or break it? :)  Maybe a reasonable middle ground would be to create a stable branch in `spotify-make` and have this spec file refer to that.  Would be interested to hear your thoughts.