I’m demoing a new version manager. I’ve been on asdf for a few years. I often use IRB (Ruby’s interactive interpreter) for basic calculations since Ruby makes such a good scripting language. When doing so today, for about the 1,000th time, I got this:

$ irb
No version is set for command irb
Consider adding one of the following versions in your config file at
ruby 3.2.1

This sort of lazy error bothers me:

• In the vast majority of situations, but especially when I’m just trying to Ruby to subtract one number from another, the exact version of Ruby I’m calling into doesn’t matter. I’d accept anything in the range of 2.0 to 3.3. If I have 3.2.1 installed, maybe just use that?
• There’s nothing actionable. I’m not told what config file it’s talking about, or how to otherwise resolve the problem.

I was told the other week that Mise does a better job of default behavior and descriptive error messages, so I’m giving it a shot.

So far, so good. Easy installation and configuration in my ~/.zshrc. I asked it to install Ruby, and it just did it. No additional plugin needed to be installed, and no specific version was required:

$ mise install ruby
mise ruby@3.3.5 ✓ installed

When entering a directory with .tool-versions, it told me immediately that a tool was missing:

$ cd owl
mise missing: ruby@3.3.4

A simple mise install walked me through installing all dependencies, including some unusual ones like Crystal, and doing so interactively so I could skip any that I didn’t want:

$ mise install
mise ⚠️ crystal is a community-developed plugin – https://github.com/asdf-community/asdf-crystal
Would you like to install crystal? Yes
mise ⚠️ postgres is a community-developed plugin – https://github.com/smashedtoatoms/asdf-postgres
Would you like to install postgres? No
mise ruby@3.3.4 ✓ installed
mise crystal@1.6.2 ✓ installed                                                                                                                                            mise run with --yes to install plugin automatically
mise asdf plugin postgres is not installed
mise Run with --verbose or MISE_VERBOSE=1 for more information