application template does not understand https urls.

Wheelie-Cyberman:~/code $ rails core -m https://github.com/some/private/raw/master/template.rb
      create  
      create  README
      ...
      create  vendor/plugins/.gitkeep
The template [/Users/phil/Public/code/https:/github.com/some/private/raw/master/template.rb] could not be loaded. Error: Could not find "/Users/phil/Public/code/https:/github.com/some/private/raw/master/template.rb" in source paths.
Wheelie-Cyberman:~/code $