Problems with setting up github hook

caddy-git seems really cool but I am at the third unsuccessful attempt at setting it up. This time I decided to ask for help before giving up.

Following is my git block in my Caddyfile.

```
git {
repo https://github.com/repo/path.git
key /etc/caddy/keys/my_id_rsa
hook /publish "my_key"
path /opt/build-dir
then hugo --destination=/var/www/blog
}
```

I suspect following errors in my log are from caddy-git

```
mkdir: cannot create directory '/var/www/.ssh': Permission denied
touch: cannot touch '/var/www/.ssh/known_hosts': No such file or directory
/tmp/caddy839530012: line 5: /var/www/.ssh/tmp_hosts: No such file or directory
/tmp/caddy839530012: line 6: /var/www/.ssh/known_hosts: No such file or directory
```
Anyhow, the push endpoint gives 404. Any help?