Honestly, I don't know why git is broken under sandbox. But this seems
fix the problem in Homebrew/homebrew#38978.
ClosesHomebrew/homebrew#39138.
Signed-off-by: Xu Cheng <xucheng@me.com>
We're (finally) working on a documented public API for Homebrew. It's currently a work in progress; a bunch of public stuff is documented and a bunch of private stuff is undocumented. Sorry about that!
The main class you should look at is {Formula}. Assume everything else is private for now.