git-send-email no longer works outside a repository?

I often use git-send-email in order to send patch files. Recently when I tried to do this outside a repository I got some cryptic failures, I'm using the master branch, git version 2.13.0.311.g0339965c70d6

I generate the patch files and copy them into a separate folder outside of the repository, and make sure everything looks good and write a cover letter, then I try to send them with

$git send-email --to=<address> 00* Can't call method "repo_path" on an undefined value at /home/jekeller/libexec/git-core/git-send-email line 1759.

Even weirder, if I move into the repository and try to send files which are outside, such as:

$git send-email --to=iwl<address> ../patches/00* fatal: /home/jekeller/git/patches/00*: '/home/jekeller/git/patches/00*' is outside repository format-patch -o /tmp/AZatqXB1uD /home/jekeller/git/patches/00*: command returned error: 128

I would expect that if you're outside a repository the command (as before) would alllow you to send files. It shouldn't strictly need to be inside a repository to function.

I found this first on pu, but as above, I checked out master and still seem to have the problem.

I'm working on a bisect now.

Thanks, Jake