Feature #18568
Updated by headius (Charles Nutter) over 2 years ago
In https://bugs.ruby-lang.org/issues/17684 there was debate about whether the `--disable-gems` flag should be removed. Several folks were in favor, since Ruby without RubyGems is fairly limited, but others wanted to keep the flag for small, fast command line scripts that do not depend on RubyGems. Lazily loading RubyGems might be a middle ground, and it has been explored in some depth by TruffleRuby: https://github.com/oracle/truffleruby/blob/master/src/main/ruby/truffleruby/core/lazy_rubygems.rb @eregon shows how this improves their startup time in this article from a couple years ago: https://eregon.me/blog/2019/04/24/how-truffleruby-startup-became-faster-than-mri.html I believe this approach has merit and could be beneficial to both CRuby and JRuby if we can collaborate on how the lazy loading should happen and figuring out where the edges are. @eregon may know some of those edges if they have run into them in TruffleRuby. A simple test of `--disable-gems` on CRuby 3.1 shows what an impact it has, which we might be able to duplicate in a lazy boot WITHOUT losing RubyGems functionality and default gem upgrading: ``` $ time ruby -e 1 real 0m0.107s user 0m0.068s sys 0m0.030s $ time ruby --disable-gems -e 1 real 0m0.019s user 0m0.007s sys 0m0.008s ``` Over 80% of CRuby's base startup is due to eagerly booting RubyGems. We can do better!