I use the envrc package to integrate my Nix-powered development environments via direnv: https://github.com/purcell/envrc https://github.com/purcell/envrc My E

I use the envrc package to integrate my Nix-powered development environments via direnv: https://github.com/purcell/envrc https://github.com/purcell/envrc My Emacs then sets up an LSP per project, and just picks up the correct LSP implementation by PATH. No per-project Emacs madness. (Though I guess you could do that if you wanted by including copies of Emacs with all the appropriate packages in your development environments.)