error: unsupported value for gpg.format: ssh

Question

Trying to setup git commit signing on my Debian box. I already have this setup on my windows box and it works fine. Not so much on my Debian box. There I get the following error when I try to commit:

siggib@htzn:/var/www/phpdemo$ git commit -m "tweak"
error: unsupported value for gpg.format: ssh
fatal: bad config variable 'gpg.format' in file '/home/siggib/.gitconfig' at line 6

Here what my config looks like

siggib@htzn:/var/www/phpdemo$ git config --list
user.name=siggib@htzn
[email protected]
user.signingkey=ssh-ed25519 AAAAC3NzaC.....
gpg.format=ssh
core.repositoryformatversion=0
core.filemode=true
core.bare=false
core.logallrefupdates=true
remote.origin.url=https://github.com/siggib007/phptest.git
remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
branch.master.remote=origin
branch.master.merge=refs/heads/master
siggib@htzn:/var/www/phpdemo$ 

I tried to google this and found nothing useful, also tried searching here with same results. Anyone have any good pointers for me?

Answer 1

SSH signing is only available with git>=2.34 (changelog). You likely have an older version.

You can check like this:

$ git --version
git version 2.25.1

Update git

If you are on Ubuntu, you can get a more recent version like this:

$ sudo add-apt-repository ppa:git-core/ppa -y
$ sudo apt-get update
$ sudo apt-get upgrade