Where is the cache stored, how can I configure the path?

[mgrebenets]

Where does buck cache server store the actual cache?
Also, can I configure the path?

I'm looking at running 2 cache servers (on different ports) on the same machine.
The reason for that is buck's current limitation with support for min sdk compiler option (facebook/buck#1803).
There's no way to set min sdk per target and in our case we have a bunch or libraries that need to be built both for iOS 9 and 10, depending on which app we plan to integrate them into.

This means a cache generated for iOS 10.0 build is not usable when building for 9.0, causing all kinds of errors.

Until buck has that option, we just have 2 different cache directories per min sdk.
So we'd want to have 2 cache servers running for each target sdk, and we need to make sure each server will have its separate storage path.