emacs-direnv VS eslint-flymake

env-commander-mode is a simple mode which allows any shell commands that Emacs invokes to run one or more commands beforehand to initialize the shell environment. There are many Emacs packages which can configure process environments, for example, direnv, but they lack the ability to go a step further and define shell functions and aliases, which is often required by "virtual environment" tools. For those who prefer interacting with shell commands via shell-command rather than shell, eshell, or term, env-commander-mode is here to assist.

I'm using nix to manage python dependencies (see excerpt of flake.nix below) but this means those python dependencies are in a /nix directory, so when lsp tries to figure out project root for them, it thinks they have nothing to do with my own project. Also I'm using emacs-direnv to transparently switch into nix environments (.envrc + use flake), so direnv (correctly) unloads my LSP executable (configured in flake.nix), so even if they should be considered totally separate projects LSP-mode doesn't know how to start up the server.

I've had a good experience with direnv[1] and emacs-direnv[2].

Direnv can automatically load an environment when you enter a directory, so it automatically "opens" virtualenvs/nix shells/etc. The Emacs direnv mode ensures that each buffer sees the direnv mode for its project directory.

I've found this to be a great compromise between automatic behavior on the one hand and transparency + control on the other—I get the right environment loaded automatically very consistently and, if something goes wrong, I can open a shell and poke around to see what's going on (is my nix shell messed up? is the right tool not loaded via direnv? etc). The only time I need to do anything manually is if I make a change to the environment and need to update Emacs about it, in which case I just run M-x direnv-update-environment.

Once I got this set up, I can just rely on executable-find to check for (and find) exactly the right tool on a per-project basis—no more worrying about global or seeing the wrong version of a tool. This also made it easy to do stuff like only run formatting if the corresponding tool is available: I add hooks to various programming language modes that only turn on lsp/formatting/etc if executable-find sees the corresponding executable.

Compared to the hassle I've had to go through helping my colleagues debug VSCode not seeing the right conda environment, virtualenv or the right version of various tools, Emacs + direnv has been a far nicer and more consistent experience.

[1]: https://direnv.net/

[2]: https://github.com/wbolster/emacs-direnv

Alternatively from what /u/hantva said, you can try using direnv and its integration with Emacs. This has a benefit of scaling better if you have more than one such project as each set of env vars is separate.

I'm using lorri and emacs-direnv together, works perfectly fine for me.

Thanks, I'll check this out if I can't get my ideal setup to work. Presume you meant this: https://github.com/wbolster/emacs-direnv ?

I first install direnv which allows me to have a different environment per directory, or in my case, a project. And there is a project that connects Emacs to this. https://github.com/wbolster/emacs-direnv

I use this to source .envrc files into my emacs environment: https://github.com/wbolster/emacs-direnv

almost. to integrate with a shell, you would indeed hook it onto the shell's prompt function. to integrate it with Emacs, you would use https://github.com/wbolster/emacs-direnv , so Emacs sees the project specific process environment too. the isolation is primarily achieved by setting up a custom PATH, PYTHON_PATH and similar vars

> Why wouldn't you want the lint error to be highlighted right as you type the code?

Why do you think you need to involve an LSP for that?. ESLint, as most linters, can take their input from stdin. That is exactly how the eslint-flymake[0] works. Lint on buffer contents, not file on disk. No JSON RPC involved.

0: https://github.com/emacs-pe/eslint-flymake/

Why would there be a canonical list given the fact that anyone can publish a package outside of Emacs core? Who would be in charge of maintaining it? From what I've seen there isn't many backends for the new API but writing your own is straightforward https://github.com/emacs-pe/eslint-flymake. Which languages/linters do you care about?