caskroom/homebrew-cask — pull request #4360 by rolandwalker (2014-05-13 13:04:20+00:00)
Title: append the .rb extension on Cask::Source::Path

Unless `.rb` is already present on the query string. Failure
to append the extension caused confusing effects, including
selective failure of "brew cask list" when invoked from
`/usr/local/bin` working directory. Fixes #4077 .
Credit to @mroth on the detective work.