It's not the commit message, but the structure of the tag command is:

'git tag [options] tag name' (among a few more things if needed). -a is
making an annotated tag (else it's too free floating and unprotected) and
"-m 'Bump to v...' is adding a message to the tag v#{version}.


2013/9/30 Gregory <notifications@github.com>

> In lib/bump.rb:
>
> > @@ -86,6 +87,7 @@ def self.commit(version, file, options)
> >        return unless File.directory?(".git")
> >        system("git add --update Gemfile.lock") if options[:bundle]
> >        system("git add --update #{file} && git commit -m 'v#{version}'")
> > +      system("git tag -a -m 'Bump to v#{version}' v#{version}") if options[:tag]
>
> Why do you display twice the version in the commit message?
>
> —
> Reply to this email directly or view it on GitHub<https://github.com/gregorym/bump/pull/32/files#r6670561>
> .
>