in lib/puppet/provider/package/tap.rb [70:80]
def uninstall
resource_name = @resource[:name].downcase
begin
Puppet.debug "Untapping #{resource_name}"
execute([command(:brew), :untap, resource_name], :failonfail => true)
rescue Puppet::ExecutionFailure => detail
raise Puppet::Error, "Could not untap resource: #{detail}"
end
end