If you change the value of the name hashing flag then simply running clean followed by compile is not enough to switch to different implementation of incremental compilation algorithm. It turns out, a full restart of sbt is required because Analysis objects are cached in memory by incremental compiler.

The caching was introduced in 135609e. The commit message said it was temporary hack but it never got reverted.

We'll need to investigate whether the hack is needed at all and if so, we'll need to clarify caching strategy.