ah, I get what the script is doing. You're using flac to run its own test. very cool. I also like the built in fail test to make sure it's working as expected.
FWIW, flac hasn't been released in a couple years but there's very recent work in the git repo.
maybe we'll get a 1.3.2 release soon:
Author: Erik de Castro Lopo <email@example.com
Date: Tue Dec 6 20:04:18 2016 +1100
doc/html/changelog.html: More updates for 1.3.2 release
but it's very easy to compile from source anyway.