fix(ci): pin Rust toolchain from .tool-versions and add MSVC target on Windows

Read rust version from .tool-versions instead of bare 'nightly' in CI
workflow, composite action, and Taskfile CI tasks. Add MSVC target to
setup-rust-toolchain on Windows runners. Fix setup-rust-windows status
check to verify x86_64-pc-windows-msvc target is installed, preventing
the task from being skipped when nightly is already present without the
MSVC standard library.

Author: pythoninthegrass

.github/actions/setup-tauri-build/action.yml

@@ -9,6 +9,13 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: Read pinned Rust toolchain from .tool-versions
+      id: rust-version
+      shell: bash
+      run: |
+        version=$(grep '^rust ' .tool-versions | awk '{print $2}')
+        echo "toolchain=${version}" >> "$GITHUB_OUTPUT"
+
     - name: Setup macOS self-hosted runner PATH
       if: runner.os == 'macOS'
       shell: bash
@@ -46,10 +53,11 @@ runs:
       run: npm ci
 
 
-    - name: Setup Rust nightly toolchain
+    - name: Setup Rust toolchain (${{ steps.rust-version.outputs.toolchain }})
       uses: actions-rust-lang/setup-rust-toolchain@v1
       with:
-        toolchain: nightly
+        toolchain: ${{ steps.rust-version.outputs.toolchain }}
+        target: ${{ runner.os == 'Windows' && 'x86_64-pc-windows-msvc' || '' }}
         cache: false
 
     - name: Setup CI environment (macOS/Linux)

.github/workflows/test.yml

@@ -40,10 +40,17 @@ jobs:
 
       - uses: actions/checkout@v6
 
+      - name: Read pinned Rust toolchain from .tool-versions
+        id: rust-version
+        shell: bash
+        run: |
+          version=$(grep '^rust ' .tool-versions | awk '{print $2}')
+          echo "toolchain=${version}" >> "$GITHUB_OUTPUT"
+
       - name: Setup Rust
         uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
-          toolchain: nightly
+          toolchain: ${{ steps.rust-version.outputs.toolchain }}
           components: clippy, rustfmt
           cache: false
 

taskfiles/ci.yml

@@ -15,11 +15,13 @@ vars:
   CONFIG: '{{.CONFIG | default ""}}'
   CONFIG_FLAG: '{{if .CONFIG}}--config {{.CONFIG}}{{end}}'
   EXE_EXT: '{{if eq OS "windows"}}.exe{{end}}'
+  PINNED_RUST:
+    sh: grep '^rust ' {{.ROOT_DIR}}/.tool-versions | awk '{print $2}'
 
 env:
   PATH: "{{.CARGO_BIN}}:{{.MISE_SHIMS}}:{{.PATH}}"
   RUSTC_WRAPPER: ""
-  RUSTUP_TOOLCHAIN: nightly
+  RUSTUP_TOOLCHAIN: "{{.PINNED_RUST}}"
 
 tasks:
   setup:
@@ -33,27 +35,28 @@ tasks:
     platforms: [darwin, linux]
     cmds:
       - curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs |
-          sh -s -- -y --default-toolchain nightly --no-modify-path
-      - rustup toolchain install nightly --profile minimal --no-self-update
-      - rustup default nightly
+          sh -s -- -y --default-toolchain {{.PINNED_RUST}} --no-modify-path
+      - rustup toolchain install {{.PINNED_RUST}} --profile minimal --no-self-update
+      - rustup default {{.PINNED_RUST}}
       - rustc --version
       - cargo --version
     status:
       - test -x "{{.CARGO_BIN}}/rustup"
       - test -x "{{.CARGO_BIN}}/rustc"
       - test -x "{{.CARGO_BIN}}/cargo"
-      - rustup run nightly rustc --version
+      - rustup run {{.PINNED_RUST}} rustc --version
 
   setup-rust-windows:
     desc: "Configure rustup nightly toolchain (Windows)"
     platforms: [windows]
     cmds:
-      - rustup toolchain install nightly --profile minimal --no-self-update --target x86_64-pc-windows-msvc
-      - rustup default nightly
+      - rustup toolchain install {{.PINNED_RUST}} --profile minimal --no-self-update --target x86_64-pc-windows-msvc
+      - rustup default {{.PINNED_RUST}}
       - rustc --version
       - cargo --version
     status:
-      - rustup run nightly rustc --version
+      - rustup run {{.PINNED_RUST}} rustc --version
+      - rustup target list --installed --toolchain {{.PINNED_RUST}} | findstr x86_64-pc-windows-msvc
 
   setup-cargo-tools:
     desc: "Install cargo-binstall and tauri-cli"