override the 'app user data directory' from command line

[benjaminfjones]

cabin is super useful, thanks for making it!

I was wondering if you could support setting the app data directory from the command line? Currently it looks like cabin uses getAppUserDataDirectory which results in $HOME/.cabin.

There are situations where you might like to have several .cabin dirs and use a flag to choose the appropriate one in each invocation. My specific use case is having to deal with an NSF mounted home directory and use haskell binaries on two different (incompatible) platforms.

[nc6]

Sorry for the delay in responding. Yes, that seems a perfectly reasonable thing to do - will take a tiny rewrite to make it work, but shouldn't be a problem. Will take a look at it maybe sometime later this week.