Handle errors -- what if `git` is missing or IO fails?

[bugeats]

Wrapping the exec call and ignoring errors is asking for trouble.

[marcbachmann]

I just run into this problem because i didn't read the docs. I assumed that there's an error instance as first argument.

[jshthornton]

+1

[noriah]

+1

[soryy708]

+1