I was trying to set up SourceTree to use GPG key signing for commits. I'm on a Mac (OS 10.13.3)
I have created keys and everything configured correctly. I can successfully commit/push stuff to a remote repo from the command line.
When I do a "gpg --list-key", in the terminal, the key shows up correctly
So then I tried do set up SourceTree and running into an issue. I've set the location of GPG in the SourceTree preferences and I am able to select the "Enable GPG key for signing commits. It automatically found my key, however, the user name that is showing up is "0", which is incorrect. The key that shows up is correct, however.

Why is it not showing the correct user? I only have one key generated and the user name does not match.
Obviously when I try to commit, I get an error:
error: gpg failed to sign the data
fatal: failed to write commit object
Anyone have any ideas?