TIL: How to Get Shell Completions in Nix Shell With Direnv

Thu, 12 Sep 2024 00:00:00 +0000

TIL: How to Get Shell Completions in Nix Shell With Direnv

When shell completions don’t work with direnv, you may need to use nix develop to load the shell manually.

Background

I am using nix-direnv, with nix devshell to autoload into my development environments. I changed the directory and the devshell is automagically loaded without me doing anything, which is great. Provides me with a bunch of tools specific for that project. With all the benefits of Nix, mainly reproducibility.

❯ z banterbus/
direnv: loading ~/projects/banterbus/.envrc
direnv: using flake
direnv: nix-direnv: Using cached dev shell
direnv: export +AR +AS +CC +CONFIG_SHELL +CXX +GOTOOLDIR +HOST_PATH +IN_NIX_SHELL +LD +NIX_BINTOOLS +NIX_BINTOOLS_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_BUILD_CORES +NIX_CC +NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_CFLAGS_COMPILE +NIX_ENFORCE_NO_NATIVE +NIX_HARDENING_ENABLE +NIX_LDFLAGS +NIX_STORE +NM +OBJCOPY +OBJDUMP +PLAYWRIGHT_BROWSERS_PATH +PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD +RANLIB +READELF +SIZE +SOURCE_DATE_EPOCH +STRINGS +STRIP +__structuredAttrs +buildInputs +buildPhase +builder +cmakeFlags +configureFlags +depsBuildBuild +depsBuildBuildPropagated +depsBuildTarget +depsBuildTargetPropagated +depsHostHost +depsHostHostPropagated +depsTargetTarget +depsTargetTargetPropagated +doCheck +doInstallCheck +dontAddDisableDepTrack +hardeningDisable +mesonFlags +name +nativeBuildInputs +out +outputs +patches +phases +preferLocalBuild +propagatedBuildInputs +propagatedNativeBuildInputs +shell +shellHook +stdenv +strictDeps +system ~PATH ~XDG_DATA_DIRS

Where my mkShell function looks something like:

{
  pkgs.mkShell {
    hardeningDisable = ["all"];
    shellHook = ''
      export PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1
      export PLAYWRIGHT_BROWSERS_PATH="${pkgs.playwright-driver.browsers}"
      ${pre-commit-check.shellHook}
    '';
    buildInputs = pre-commit-check.enabledPackages;
    packages = with pkgs; [
      # TODO: workout how to use go env
      # goEnv
      gomod2nix
      go_1_22
      playwright-test

      goose
      air
      golangci-lint
      gotools
      gotestsum
      gocover-cobertura
      go-task
      go-mockery
      goreleaser
      golines

      tailwindcss
      templ
      sqlc
    ];
  }
}

You can see I have certain tools I want other developers to have access to like go-task, which they will automatically get when they load into the devshell.

Issue

This is all great; however, I have noticed that shell completions stopped working. Where I can normally do task

❯ task tests:e2e
build:dev  (Build the app for development, generates all the files needed for the binary.)  generate:sqlc  (Generates the code to interact with SQL DB.)
coverage                            (Run the integration tests and gets the code coverage)  lint                                      (Runs the linter.)
dev                                       (Start the app in dev mode with live-reloading.)  release                              (Release the CLI tool.)
docker:build                                            (Builds a Docker image using Nix.)  tests                                  (Runs all the tests.)
docker:load                                (Loads the Docker image from tar (in results).)  tests:e2e                  (Runs e2e tests with playwright.)
docker:publish                                                (Publishes the Docker image)  tests:integration          (Runs all the integration tests.)
format                                                               (Runs the formatter.)  tests:unit                        (Runs all the unit tests.)

However, in the devshell this does not work until I load into the shell manually nix develop. Which does defeat the purpose of using nix-direnv as you need to manually run a command now.

I don’t know what causes this and will do a deeper dive at some point 🤔.

TIL: How to Set up Layouts in Zellij That Use Direnv and Nix

Mon, 18 Mar 2024 00:00:00 +0000

TIL: How to Set up Layouts in Zellij That Use Direnv and Nix

I have been using Zellij for a while now. I tried to set up layouts for one of my personal projects. So that we could have tests and linting running and any other tasks we may want whilst doing development ¹.

However, I had an issue working out how to call commands that required direnv and nix to set up development environments. In my case, my nix dev shell installed the go-task tool to run tasks such as task lint or task tests. However the shell that zellij was running the commands in for the layout did not load my Nix dev shell, so the go-task binary was not available.

So to fix this, we need to do something like this layout.kdl:

layout {
    pane size=1 borderless=true {
        plugin location="zellij:tab-bar"
    }
    pane {
        command "fish"
        args "-c" "direnv exec . task lint"
    }
    pane {
        command "fish"
        args "-c" "direnv exec . task tests"
    }
    pane {
        command "docker-compose"
        args "up" "--build -d"
    }
}

Where the key being we need to execute the direnv environment i.e. direnv exec ., then we can run commands like normal. Where direnv .envrc file contains use flake. That’s it! If you want Zellij to use direnv and load your nix flake dev shell, you have to add a bit of boilerplate, which is not ideal but

https://github.com/zellij-org/zellij/issues/2294 ↩︎

Direnv on Haseeb Majid

TIL: How to Get Shell Completions in Nix Shell With Direnv

Background

Issue

TIL: How to Set up Layouts in Zellij That Use Direnv and Nix