Feedback on this post is welcomed on Discuss!

We are very excited to announce the first (and hopefully only) release candidate for opam 2.2.0.

We've squashed a few more bugs and we consider this to be ready for the final release. You can view the full list of changes in the release note.

We invite users to test it one final time just in case there are any previously unnoticed bugs!


  • Fix opam upgrade wanting to keep rebuilding the compiler (as now it contains an x-env-path-rewrite field)
  • Provide defaults so opam init -y no longer asks questions on Windows
  • Fix when there are more than 9 options (can happen on Windows)

A couple more improvements were made and bugs were fixed. The single API change is also denoted in the release note. This release also includes PRs extending the tests.

Try it!

In case you plan a possible rollback, you may want to first backup your ~/.opam or $env:LOCALAPPDATA\opam directory.

The upgrade instructions are unchanged:

  1. Either from binaries: run

For Unix systems

bash -c "sh <(curl -fsSL --version 2.2.0~rc1"

or from PowerShell for Windows systems

Invoke-Expression "& { $(Invoke-RestMethod }"

or download manually from the Github "Releases" page to your PATH.

  1. Or from source, manually: see the instructions in the README.

You should then run:

opam init --reinit -ni

Please report any issues to the bug-tracker.

Thanks for trying this new release out, and we hope you will enjoy the new features of opam 2.2!