Mock "Bundler.original_env" in spec
Mock "Bundler.original_env" in spec

Mocking just ENV is not enough, because Bundler reads it once in the beginning.
See https://github.com/bundler/bundler/blob/396692631648eda130bdd291e91895fa37e75478/lib/bundler.rb#L18

cargomedia/komenda,njam/komenda