I was unable to run the Clojure tests due to this problem. There is a test that hardcodes a port and something else on my machine happened to be using that port.
The patch avoids binding a hard-coded port in the test.
I used to try running the prescreen tests in parallel for two different JDKs on the same machine, and I probably stopped doing that because of this. My use case is a very unusual one, and not a good reason to change this by itself, but my use case certainly made this conflict happen regularly.
No good reason not to fix it! Silly test.