$ hub clone geemus/excon Cloning into 'excon'... fatal: remote error: The unauthenticated git protocol on port 9418 is no longer supported. Please see https://github.blog/2021-09-01-improving-git-protocol-security-github/ for more information. The manpage mentions a way of switching to https, but using git:// as a default does not work anymore.
git:// is also mentioned in the package description. Please fix that too.