Fixes #3628. With environment filtering, hg was no longer in the path, so make sure to provide the path when calling hg commands. last_commit was the source of the problem in #3628 but I fixed source_modified_time as well. I didn't see any others with this problem.
Library
This directory contains all the code run by the official brew and brew cask commands in Homebrew and all formulae (package descriptions) in taps (repositories containing formulae) in Taps subdirectories.