Fix: Run the version detection steps in the selected rust-src-dir directory.

This should enable the version selection even without a default
toolchain installed.

Fixes #74.

.github/dependabot.yml

@@ -8,4 +8,4 @@ updates:
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "monthly"
+      interval: "weekly"

.github/workflows/autotag-releases.yml

@@ -15,7 +15,7 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Get version from tag
         id: tag_name
         run: |

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
           - "beta"
           - "stable"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       # Test toolchain file support
       - name: Write rust-toolchain.toml
@@ -93,7 +93,7 @@ jobs:
     name: Cache
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Install Rust
         uses: ./

CHANGELOG.md

@@ -7,6 +7,44 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.15.2] - 2025-10-04
+
+* Fix: Run the version detection steps in the selected `rust-src-dir` directory.
+    This should enable the version selection even without a default toolchain installed.
+    Fixes #74.
+
+## [1.15.1] - 2025-09-23
+
+* Update `Swatinem/rust-cache` to v2.8.1
+
+## [1.15.0] - 2025-09-14
+
+* Add support for non-root source directory.
+    Accept source code and `rust-toolchain.toml` file in subdirectories of the repository.
+    Adds a new parameter `rust-src-dir` that controls the lookup for toolchain files and sets a default value for the `cache-workspace` input. (#69 by @Kubaryt)
+
+## [1.14.1] - 2025-08-28
+
+* Pin `Swatinem/rust-cache` action to a full commit SHA (#68 by @JohnTitor)
+
+## [1.14.0] - 2025-08-23
+
+* Add new parameters `cache-all-crates` and `cache-workspace-crates` that are propagated to `Swatinem/rust-cache` as `cache-all-crates` and `cache-workspace-crates`
+
+## [1.13.0] - 2025-06-16
+
+* Add new parameter `cache-provider` that is propagated to `Swatinem/rust-cache` as `cache-provider` (#65 by @mindrunner)
+
+## [1.12.0] - 2025-04-23
+
+* Add support for installing rustup on Windows (#58 by @maennchen)
+    This adds support for using Rust on the GitHub provided Windows ARM runners.
+
+## [1.11.0] - 2025-02-24
+
+* Add new parameter `cache-bin` that is propagated to `Swatinem/rust-cache` as `cache-bin` (#51 by @enkhjile)
+* Add new parameter `cache-shared-key` that is propagated to `Swatinem/rust-cache` as `shared-key` (#52 by @skanehira)
+
 ## [1.10.1] - 2024-10-01
 
 * Fix problem matcher for rustfmt output.

README.md

@@ -6,7 +6,7 @@ Caching for Rust tools and build artifacts is enabled.
 Environment variables are set to optimize the cache hits.
 [Problem Matchers] are provided for build messages (cargo, clippy) and formatting (rustfmt).
 
-The action is heavily inspired by *dtolnay*'s <https://github.com/dtolnay/rust-toolchain> and extends it with further features.
+The action is heavily inspired by _dtolnay_'s <https://github.com/dtolnay/rust-toolchain> and extends it with further features.
 
 ## Example workflow
 
@@ -21,7 +21,7 @@ jobs:
     name: cargo test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: actions-rust-lang/setup-rust-toolchain@v1
       - run: cargo test --all-features
 
@@ -30,7 +30,7 @@ jobs:
     name: cargo fmt
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       # Ensure rustfmt is installed and setup problem matcher
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
@@ -48,19 +48,25 @@ If no `toolchain` value or toolchain file is present, it will default to `stable
 First, all items specified in the toolchain file are installed.
 Afterward, the `components` and `target` specified via inputs are installed in addition to the items from the toolchain file.
 
-| Name                | Description                                                                                                              | Default       |
-| ------------------- | ------------------------------------------------------------------------------------------------------------------------ | ------------- |
-| `toolchain`         | Comma-separated list of Rustup toolchain specifier e.g. `stable`, `nightly`, `1.42.0`.  The last version is the default. | stable        |
-| `target`            | Additional target support to install e.g. `wasm32-unknown-unknown`                                                       |               |
-| `components`        | Comma-separated string of additional components to install e.g. `clippy, rustfmt`                                        |               |
-| `cache`             | Automatically configure Rust cache (using [`Swatinem/rust-cache`])                                                       | true          |
-| `cache-directories` | Propagates the value to [`Swatinem/rust-cache`]                                                                          |               |
-| `cache-workspaces`  | Propagates the value to [`Swatinem/rust-cache`]                                                                          |               |
-| `cache-on-failure`  | Propagates the value to [`Swatinem/rust-cache`]                                                                          | true          |
-| `cache-key`         | Propagates the value to [`Swatinem/rust-cache`] as `key`                                                                 |               |
-| `matcher`           | Enable problem matcher to surface build messages and formatting issues                                                   | true          |
-| `rustflags`         | Set the value of `RUSTFLAGS` (set to empty string to avoid overwriting existing flags)                                   | "-D warnings" |
-| `override`          | Setup the last installed toolchain as the default via `rustup override`                                                  | true          |
+| Name                     | Description                                                                                                                                                                        | Default       |
+| ------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------- |
+| `toolchain`              | Comma-separated list of Rustup toolchain specifier e.g. `stable`, `nightly`, `1.42.0`. The last version is the default.                                                            | stable        |
+| `target`                 | Additional target support to install e.g. `wasm32-unknown-unknown`                                                                                                                 |               |
+| `components`             | Comma-separated string of additional components to install e.g. `clippy, rustfmt`                                                                                                  |               |
+| `cache`                  | Automatically configure Rust cache (using [`Swatinem/rust-cache`])                                                                                                                 | true          |
+| `cache-directories`      | Propagates the value to [`Swatinem/rust-cache`]                                                                                                                                    |               |
+| `cache-workspaces`       | Propagates the value to [`Swatinem/rust-cache`]. Influenced by the value of `rust-src-dir`.                                                                                        |               |
+| `cache-on-failure`       | Propagates the value to [`Swatinem/rust-cache`]                                                                                                                                    | true          |
+| `cache-key`              | Propagates the value to [`Swatinem/rust-cache`] as `key`                                                                                                                           |               |
+| `cache-shared-key`       | Propagates the value to [`Swatinem/rust-cache`] as `shared-key`                                                                                                                    |               |
+| `cache-bin`              | Propagates the value to [`Swatinem/rust-cache`] as `cache-bin`                                                                                                                     | true          |
+| `cache-provider`         | Propagates the value to [`Swatinem/rust-cache`] as `cache-provider`                                                                                                                | 'github'      |
+| `cache-all-crates`       | Propagates the value to [`Swatinem/rust-cache`] as `cache-all-crates`                                                                                                              | false         |
+| `cache-workspace-crates` | Propagates the value to [`Swatinem/rust-cache`] as `cache-workspace-crates`                                                                                                        | false         |
+| `matcher`                | Enable problem matcher to surface build messages and formatting issues                                                                                                             | true          |
+| `rustflags`              | Set the value of `RUSTFLAGS` (set to empty string to avoid overwriting existing flags)                                                                                             | "-D warnings" |
+| `override`               | Setup the last installed toolchain as the default via `rustup override`                                                                                                            | true          |
+| `rust-src-dir`           | Path from root directory to directory with the Rust source directory (if its not in the root of the repository). Sets a default value for `cache-workspaces` that enables caching. |               |
 
 [`Swatinem/rust-cache`]: https://github.com/Swatinem/rust-cache
 
@@ -69,10 +75,10 @@ Afterward, the `components` and `target` specified via inputs are installed in a
 By default, this action sets the `RUSTFLAGS` environment variable to `-D warnings`.
 However, rustflags sources are mutually exclusive, so setting this environment variable omits any configuration through `target.*.rustflags` or `build.rustflags`.
 
-* If `RUSTFLAGS` is already set, no modifications of the variable are made and the original value remains.
-* If `RUSTFLAGS` is unset and the `rustflags` input is empty (i.e., the empty string), then it will remain unset.
-    Use this, if you want to prevent the value from being set because you make use of `target.*.rustflags` or `build.rustflags`.
-* Otherwise, the environment variable `RUSTFLAGS` is set to the content of `rustflags`.
+- If `RUSTFLAGS` is already set, no modifications of the variable are made and the original value remains.
+- If `RUSTFLAGS` is unset and the `rustflags` input is empty (i.e., the empty string), then it will remain unset.
+  Use this, if you want to prevent the value from being set because you make use of `target.*.rustflags` or `build.rustflags`.
+- Otherwise, the environment variable `RUSTFLAGS` is set to the content of `rustflags`.
 
 To prevent this from happening, set the `rustflags` input to an empty string, which will
 prevent the action from setting `RUSTFLAGS` at all, keeping any existing preferences.
@@ -88,6 +94,16 @@ You can read more rustflags, and their load order, in the [Cargo reference].
 | `rustup-version` | Version as reported by `rustup --version`   |
 | `cachekey`       | A short hash of the installed rustc version |
 
+## Dependencies
+
+The action works best on the GitHub-hosted runners, but can work on self-hosted ones too, provided the necessary dependencies are available.
+PRs to add support for more environments are welcome.
+
+- bash 5
+- brew (macOS only)
+- rustup or curl
+- using other node actions
+
 ## License
 
 The scripts and documentation in this project are released under the [MIT

action.yml

@@ -32,12 +32,31 @@ inputs:
     description: "Additional non workspace directories to be cached, separated by newlines."
     required: false
   cache-on-failure:
-    description: "Also cache on workflow failures"
+    description: "Cache even if the build fails."
     default: "true"
     required: false
   cache-key:
     description: "An additional cache key that is added alongside the automatic `job`-based cache key and can be used to further differentiate jobs."
     required: false
+  cache-shared-key:
+    description: "A cache key that is used instead of the automatic `job`-based key, and is stable over multiple jobs."
+    required: false
+  cache-bin:
+    description: "Determines whether to cache ${CARGO_HOME}/bin."
+    required: false
+    default: "true"
+  cache-provider:
+    description: "Determines which provider to use for caching. Options are github, buildjet, or warpbuild. Defaults to github."
+    required: false
+    default: "github"
+  cache-all-crates:
+    description: "Determines which crates are cached. If `true` all crates will be cached, otherwise only dependent crates will be cached."
+    required: false
+    default: "false"
+  cache-workspace-crates:
+    description: "Determines which crates are cached. If `true` all crates will be cached, otherwise only dependent crates will be cached."
+    required: false
+    default: "false"
   matcher:
     description: "Enable the Rust problem matcher"
     required: false
@@ -50,6 +69,9 @@ inputs:
     description: "Setup the last installed toolchain as the default via `rustup override`"
     required: false
     default: "true"
+  rust-src-dir:
+    description: "Specify path from root directory to the Rust source directory. By default root directory will be used."
+    required: false
 
 outputs:
   rustc-version:
@@ -123,13 +145,20 @@ runs:
       run: echo "::add-matcher::${{ github.action_path }}/rust.json"
 
     - name: Install rustup, if needed
-      if: runner.os != 'Windows'
       shell: bash
       run: |
         if ! command -v rustup &> /dev/null ; then
           curl --proto '=https' --tlsv1.2 --retry 10 --retry-connrefused -fsSL "https://sh.rustup.rs" | sh -s -- --default-toolchain none -y
-          echo "${CARGO_HOME:-$HOME/.cargo}/bin" >> $GITHUB_PATH
+
+          # Resolve the correct CARGO_HOME path depending on OS
+          if [[ "$RUNNER_OS" == "Windows" ]]; then
+            echo "${CARGO_HOME:-$USERPROFILE/.cargo}/bin" | sed 's|/|\\|g' >> $GITHUB_PATH
+          else
+            echo "${CARGO_HOME:-$HOME/.cargo}/bin" >> $GITHUB_PATH
+          fi
         fi
+      env:
+        RUNNER_OS: "${{ runner.os }}"
 
     - name: rustup toolchain install ${{inputs.toolchain || 'stable'}}
       env:
@@ -137,9 +166,23 @@ runs:
         targets: ${{inputs.target}}
         components: ${{inputs.components}}
         override: ${{inputs.override}}
+        rust_src_dir: ${{inputs.rust-src-dir}}
       shell: bash
       run: |
-        if [[ -z "$toolchain" && ( -f "rust-toolchain" || -f "rust-toolchain.toml" ) ]]
+        # Check if value is set
+        if [[ -n "$rust_src_dir" ]]
+        then
+          # If value is set the directory must exist
+          if [[ -d "$rust_src_dir" ]]
+          then
+            cd "$rust_src_dir"
+          else
+            echo "'rust-src-dir' does not point to an existing directory" >&2
+            echo "The value of 'rust-src-dir' is: ${rust_src_dir}" >&2
+            exit 1
+          fi
+        fi
+        if [[ -z "$toolchain" && ( -f "rust-toolchain" || -f "rust-toolchain.toml") ]]
         then
           # Install the toolchain as specified in the file
           # rustup show is the old way that implicitly installed a toolchain
@@ -168,6 +211,8 @@ runs:
     - id: versions
       name: Print installed versions
       shell: bash
+      # Switch to the Rust sub-directory
+      working-directory: ${{inputs.rust-src-dir || '.'}}
       run: |
         echo "rustc-version=$(rustc --version)" >> $GITHUB_OUTPUT
         rustc --version --verbose
@@ -194,9 +239,14 @@ runs:
 
     - name: Setup Rust Caching
       if: inputs.cache == 'true'
-      uses: Swatinem/rust-cache@v2
+      uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
       with:
-        workspaces: ${{inputs.cache-workspaces}}
+        workspaces: ${{ inputs.cache-workspaces || inputs.rust-src-dir }}
         cache-directories: ${{inputs.cache-directories}}
         cache-on-failure: ${{inputs.cache-on-failure}}
+        cache-bin: ${{inputs.cache-bin}}
+        cache-provider: ${{inputs.cache-provider}}
+        cache-all-crates: ${{inputs.cache-all-crates}}
+        cache-workspace-crates: ${{inputs.cache-workspace-crates}}
         key: ${{inputs.cache-key}}
+        shared-key: ${{inputs.cache-shared-key}}