chore: replace nix with mise

.github/actions/setup-mise/action.yaml

@@ -0,0 +1,10 @@
+name: "Setup mise"
+description: "This action installs the tools pinned in mise.toml"
+runs:
+  using: "composite"
+  steps:
+    - name: Setup mise
+      uses: jdx/mise-action@82a612c5ab8bcda7cc5db6b7e81a8e7584c3dc6e # v5.2.3
+      with:
+        version: 2026.10.19
+        cache: false

.github/workflows/ci.yml

@@ -42,8 +42,8 @@ jobs:
         with:
           xcode-version: "26.5.0"
 
-      - name: Setup Nix
-        uses: ./.github/actions/nix-devshell
+      - name: Setup mise
+        uses: ./.github/actions/setup-mise
 
       - run: make test
 
@@ -63,8 +63,8 @@ jobs:
         with:
           xcode-version: "26.5.0"
 
-      - name: Setup Nix
-        uses: ./.github/actions/nix-devshell
+      - name: Setup mise
+        uses: ./.github/actions/setup-mise
 
       - run: make fmt
 
@@ -79,8 +79,8 @@ jobs:
           fetch-tags: true
           persist-credentials: false
 
-      - name: Setup Nix
-        uses: ./.github/actions/nix-devshell
+      - name: Setup mise
+        uses: ./.github/actions/setup-mise
 
       - run: make lint
         env:

.github/workflows/release.yml

@@ -35,6 +35,7 @@ jobs:
     env:
       # See the test job in ci.yml.
       DEPOT_XCODE_CACHE_ENABLED: 0
+      out: ${{ github.workspace }}/release
     steps:
       - name: Checkout
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
@@ -48,8 +49,8 @@ jobs:
         with:
           xcode-version: "26.5.0"
 
-      - name: Setup Nix
-        uses: ./.github/actions/nix-devshell
+      - name: Setup mise
+        uses: ./.github/actions/setup-mise
 
       - name: Authenticate to Google Cloud
         id: gcloud_auth
@@ -81,7 +82,7 @@ jobs:
         uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
         with:
           name: coder-desktop-build
-          path: ${{ github.workspace }}/outputs/out
+          path: ${{ env.out }}
           retention-days: 7
 
       # Upload to release in non-dry-run mode
@@ -121,8 +122,8 @@ jobs:
           fetch-tags: true
           persist-credentials: false
 
-      - name: Setup Nix
-        uses: ./.github/actions/nix-devshell
+      - name: Setup mise
+        uses: ./.github/actions/setup-mise
 
       - name: Update homebrew-coder
         env:

.gitignore

@@ -1,9 +1,5 @@
-# Created by https://www.toptal.com/developers/gitignore/api/xcode,jetbrains,macos,direnv,swift,swiftpm,objective-c
-# Edit at https://www.toptal.com/developers/gitignore?templates=xcode,jetbrains,macos,direnv,swift,swiftpm,objective-c
-
-### direnv ###
-.direnv
-.envrc
+# Created by https://www.toptal.com/developers/gitignore/api/xcode,jetbrains,macos,swift,swiftpm,objective-c
+# Edit at https://www.toptal.com/developers/gitignore?templates=xcode,jetbrains,macos,swift,swiftpm,objective-c
 
 ### JetBrains ###
 # Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider
@@ -294,7 +290,7 @@ xcuserdata
 **/.vscode/**
 buildServer.json
 
-# End of https://www.toptal.com/developers/gitignore/api/xcode,jetbrains,macos,direnv,swift,swiftpm,objective-c
+# End of https://www.toptal.com/developers/gitignore/api/xcode,jetbrains,macos,swift,swiftpm,objective-c
 
 *.entitlements
 app-signing.keychain-db

CONTRIBUTING.md

@@ -17,61 +17,32 @@ and bundle identifiers.
 
 ## Setting Up the Development Environment
 
-To ensure a consistent and reliable development environment, we recommend using
-[**Nix**](https://nix.dev/) with Flake support. All the tools required for
-development are defined in the `flake.nix` file.
+To ensure a consistent and reliable development environment, we use
+[**mise**](https://mise.jdx.dev/) to install the tools required for development.
+Their versions are pinned in `mise.toml`.
 
-**Note:** Nix is the only supported development environment for this project.
-While setups outside of Nix may work, we do not support custom tool installations
-or address issues related to missing path setups or other tooling installation
-problems. Using Nix ensures consistency across development environments and avoids
-these potential issues.
+**Note:** mise is the only supported way to install these tools. While other
+setups may work, we do not support custom tool installations or address issues
+related to missing path setups or other tooling installation problems. For
+example, a Homebrew `swiftformat` may format the code differently from CI.
 
-### Installing Nix with Flakes Enabled
-
-If you don’t already have Nix installed, you can:
-
-1. Use the [Determinate Systems installer](https://nixinstaller.com/) for a
-   simple setup.
-2. Alternatively, use the [official installer](https://nixos.org/download.html)
-   and enable Flake support by adding the following to your Nix configuration:
-
-   ```nix
-   experimental-features = nix-command flakes
-   ```
-
-This project does **not** support non-Flake versions of Nix.
-
-### Entering the Development Environment
-
-Run the following command to enter the development environment with all necessary
-tools:
-
-```bash
-nix develop
-```
-
-### Using `direnv` for Environment Automation (Optional)
-
-As an optional recommendation, you can use [`direnv`](https://direnv.net/) to
-automatically load and unload the Nix development environment when you navigate
-to the project directory. After installing `direnv`, enable it for this project by:
-
-1. Adding the following line to your `.envrc` file in the project directory:
+1. [Install mise](https://mise.jdx.dev/installing-mise.html).
+2. From the project directory, [trust](https://mise.jdx.dev/cli/trust.html) its
+   `mise.toml`. mise asks for this because the file changes mise settings:
 
    ```bash
-   use flake
+   mise trust
    ```
 
-2. Allowing the `.envrc` file by running:
+3. Install the tools:
 
    ```bash
-   direnv allow
+   mise install
    ```
 
-With `direnv`, the development environment will automatically be set up whenever
-you enter the project directory. This step is optional but can significantly
-streamline your workflow.
+4. [Activate mise in your shell](https://mise.jdx.dev/getting-started.html#activate-mise),
+   so the pinned tools are on your `PATH` whenever you are in the project
+   directory.
 
 ## Generating the Xcode Project Files
 

Makefile

@@ -2,6 +2,10 @@
 SHELL := bash
 .SHELLFLAGS := -ceu
 
+ifeq ($(filter oneshell,$(.FEATURES)),)
+$(error GNU Make 3.82 or later is required for .SHELLFLAGS, but this is $(MAKE_VERSION). Install the tools with mise, see CONTRIBUTING.md)
+endif
+
 # This doesn't work on directories.
 # See https://stackoverflow.com/questions/25752543/make-delete-on-error-for-directory-targets
 .DELETE_ON_ERROR: