Commit failed error with GPG signing turned on

Description

I recently started seeing this with the atom/github package as well. See that report for more details: https://github.com/atom/github/issues/737

When I try to make a commit I get an error message:

Commit failed - exit code 128 received, with output: 'error: cannot run gpg: No such file or directory
error: gpg failed to sign the data
fatal: failed to write commit object'

Version

GitHub Desktop version: 0.0.37

OS version: OS X El Capitan (10.11.6)

Steps to Reproduce

1. Make a change to a file in a repository
2. Type a commit message
3. Click Commit button
4. Error Message:

Expected behaviour: I expect the commit to succeed.

Actual behaviour: I get the above error message, changes remain in the Changes tab and are not committed.

Reproduces how often: 100%

Logs

I couldn’t find log files for Desktop beta. Are there any?

Additional Information

I have git configured to sign every commit:

$ git config --global --get commit.gpgsign
true

And my git version:

$ git --version
git version 2.12.0

[bwestover]

In case it helps someone, the workaround I’m using for now is to disable gpg signing with a repository level git config.

From within the repo path where I want to disable automatic gpg signing:

$ git config commit.gpgsign false

[HajarElkoumikhi]

I tried this out and it works !

git config --global commit.gpgsign false