I am actually in the (very slow) process if making the BEAM work better within Nix (I have posted about this elsewhere on the forum before, maybe look for that for some more information). I am writing a tool right now that will convert a rebar3 or mix project into a default.nix file similar to tools for other languages.
Automatic context switching
Like you said, there is none. You will just need to get used to calling nix-shell or some other tool to get where you want. But this isn’t necessarily a bad thing either. You are being explicit about what you want.
Limited versions
This is also true. But I don’t really see having only the latest patch for each minor version available. Everything should be backward compatible (assuming you are not relying on internal functionalty, but there is already a post about that elsewhere). So it is just bug fixes and such.
Time for a new version
Again, true. This is mostly true about any OS package manager. Nix needs to make sure that all of the packages in the ecosystem play nicely together. With that said, I did make it super easy to make your own version of Elixir if it is not found in nixpkgs. Just take a look at how we define v1.7 and the corresponding entry to actually build it. If you need a version that is not listed or has not yet been updated. Feel free to add your own for your project!
Contributions
Just like you do not need asdf installed to contribute to a package that has asdf, you do not NEED to install Nix to contribute to a package that uses it. Just make sure you outline your requirements in your contribution guide.
For the vast majority of uses, I would currently say to stay away from Nix and NixOS for BEAM specific work. Or if you want to use NixOS, use it like a regular linux for the time being (I am doing this for a couple things).
For anyone else that REALLY wants to use Nix and NixOS right now, send me a message and we will see if we can get the BEAM integration moving a little faster.
