I think if you edit the .tool-versions file manually, you’ll need to run asdf install elixir [new-version] afterward (where [new-version] is the version you changed the file to use).
I finally ran into this issue recently, and there wasn’t a lot of material on the subject that I could find:
I guess the good news is more or less that the process is pretty straightforward. Just bump and install the new Erlang + Elixir versions, run the tests, and fix any issues that come up. The compiler should show warnings for any new deprecations.
Don’t forget to bump the dependencies in your mix.exs file as well:
mix hex.outdated
https://hexdocs.pm/hex/Mix.Tasks.Hex.Outdated.html
mix deps.update --all
https://hexdocs.pm/mix/Mix.Tasks.Deps.Update.html
And if you ended up adding any dependencies at some point that are no longer needed, then you can remove those as well:
