Michał (mihao, Helpling)'s second wroclove.rb 2023 lightning talk, 'The Good the Bad and the Ugly' of Ruby Packer. Follows his earlier talk on Helpling ToolBelt. Problem: running a Ruby CLI as a multi-file script across multiple Ruby versions, with bundler demanding a Gemfile in the current directory even for scripts that don't need gems (painful with Docker). Surveys options: Traveling Ruby by the Fusion Passenger team (2014-era pre-built Ruby packaged into a directory) — last real contribution around 2014, brief 2021 activity, currently stuck on Ruby 2.4 and not recommended. Ruby Packer is the modern alternative: compiles Ruby with your code embedded in a virtual file system, patches Ruby to require files through it, transparent to the developer. Good: no worries about gems or Ruby installation, single binary. Bad: binary size (around 30MB). Ugly: original author stopped maintaining ~2 years ago; various forks exist, and he found one on Reddit that embeds Ruby 3.1.3 and works well. Cross-compilation not possible — must build on Mac for Mac and on Linux for Linux; not everything is statically compiled, so the Ubuntu build may not run on Fedora/Arch or older Ubuntu. Otherwise a nice way to ship a CLI tool without worrying about the environment.