Hi, By recent change, gem_prelude always requires rubygems/defaults.rb and other rubygems related files. It's not my intention. I don't want the bare interpreter to rely on other libraries, until it's really needed. Plain execution should be done without loading any other libraries. That's the very reason behind pre-loaded prelude.rb and gem_prelude.rb. It already made my testing difficult. So, Eric, could you avoid mandatory requiring rubygems from gem_prelude, please? It should be done lazily. matz.