/usr/lib/ruby/vendor_ruby/bundler/templates/newgem/exe/newgem.tt is in ruby-bundler 1.13.6-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | #!/usr/bin/env ruby
require "<%= config[:namespaced_path] %>"
|