Module doesn't work when www-data user doesn't have write access.

[sminnee]

Kind of obvious, but still a blocker for using this on many environments.

Not sure what should be done to fix this, if anything.

[hafriedlander]

It shouldn't be triggering when isLive for exactly this reason. The assumption is that on dev boxes you do have write access, and then commit the built css, and then on the live box where you don't have write access those committed css files get used,