This post is relevant as of mid-October 2022, and linked to this issue-turned into a discussion I opened on ruby-build.

I am positive that ruby-build will be patched and contain the necessary code to install ruby with Xcode 14 on Monterey OS and M1 chip, but maybe you can find this post useful to get you unstuck in the meantime.

I got a brand new Apple machine, with a fancy M1 chip, Monterey 12.6 and Xcode 14. I was trying to install the whole setup of the Ruby project I’m working on. I need ruby 3.1.2.

The error manifested as such, during the bundle step:

warning: It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your ruby.

The error is not libyaml itself (you can brew install it as much as you want, it won’t do) nor the psych gem that is using it. The issue is that Ruby is not being installed.

I had rvm installed. Plus maybe another version of ruby installed via brew as well as the system ruby (untouchable/shouldn’t mess with it). Certainly a bit of a mess.

I tried uninstalling rvm using the implode command, and use asdf instead, following the laptop script some folks often use at thoughtbot, that I had not used before.

asdf installs ruby leveraging rbenv’s ruby-build and that’s how we found the reported bug, that’s being patched.

This was still failing, downloading an alternative (to the existing on the machine) own version of openssl, as we noticed. (and maybe other alternative moves)

Installing ruby from its source, running ./configure and make was outputting the same error.

Meanwhile we decided to downgrade Xcode to 13 and try harder.

At this point we removed all the content of ~/.asdf and reinstalled the ruby plugin (and node’s):

asdf plugin-add "ruby" "https://github.com/asdf-vm/asdf-ruby.git"
asdf plugin-add "nodejs" "https://github.com/asdf-vm/asdf-nodejs.git"

We installed ruby using purely ruby-install this time, making sure we nuked all the rvm leftover stuff as well using rvm implode -> yes We are still not sure why rvm’s ruby-build wouldn’t do the same thing. (it should)

Using ruby-install directly ensures that the install command fetches the package manager version of the needed libraries, used as arguments when running the ./configure when building ruby.

This install was successful, and placed our ruby 3.1.2 into the ~/.rubies/ruby-3.1.2 folder.

By now, /.asdf should also exist.

We need to copy the artifacts of that installation we did using ruby-install to be available to asdf as well.

We ran:

ruby-install --install-dir ~/.asdf/installs/ruby/3.1.2 ruby 3.1.2

The other thing that we needed to remove any leftover junk from the $PATH on my .zshrc file, that got messed up big times, after all these clunky initial attempts of mine. As well as the source path for asdf adding to .zshrc:

. /opt/homebrew/opt/asdf/libexec/asdf.sh

Good luck! 😉

Thanks to Nick for the immense help. And thanks to Fritz for showing me how ruby actually gets installed.