Detect and support Linux ARM runners for both Miniconda and Miniforge

.github/workflows/example-15.yml

@@ -0,0 +1,78 @@
+name: "Example 15: Linux ARM"
+
+on:
+  pull_request:
+    branches:
+      - "*"
+  push:
+    branches:
+      - "develop"
+      - "main"
+      - "master"
+  schedule:
+    # Note that cronjobs run on master/main by default
+    - cron: "0 0 * * *"
+
+jobs:
+  example-15:
+    # prevent cronjobs from running on forks
+    if:
+      (github.event_name == 'schedule' && github.repository ==
+      'conda-incubator/setup-miniconda') || (github.event_name != 'schedule')
+    name: Ex15 (os=${{ matrix.os }} variant=${{ matrix.variant }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: ["ubuntu-24.04-arm"]
+        variant: ["Miniforge3", "Miniconda", "no-variant", "empty-with"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./
+        if: matrix.variant == 'Miniforge3'
+        id: setup-miniforge
+        continue-on-error: true
+        with:
+          auto-update-conda: true
+          miniforge-variant: ${{ matrix.variant }}
+          miniforge-version: latest
+      - uses: ./
+        if: matrix.variant == 'Miniconda'
+        id: setup-miniconda
+        continue-on-error: true
+        with:
+          auto-update-conda: true
+          miniconda-version: latest
+      - uses: ./
+        if: matrix.variant == 'no-variant'
+        id: setup-miniconda-no-variant
+        continue-on-error: true
+        with:
+          miniforge-version: latest
+      - uses: ./
+        if: matrix.variant == 'empty-with'
+        id: setup-miniconda-empty-with
+        continue-on-error: true
+      - name: Conda info
+        shell: bash -el {0}
+        run: conda info
+      - name: Conda list
+        shell: bash -el {0}
+        run: conda list
+      - name: Environment
+        shell: bash -el {0}
+        run: printenv | sort
+      - name: Create an environment
+        shell: bash -el {0}
+        run: conda create -n unused --dry-run zlib
+      - name: Run mamba
+        if: matrix.variant == 'Miniforge3'
+        shell: bash -el {0}
+        run: mamba --version
+      - name: Install Python
+        shell: bash -el {0}
+        run: conda install -y python
+      - name: Check architecture
+        shell: bash -el {0}
+        run: |
+          python -c "import platform; assert platform.machine() == 'aarch64', platform.machine()"

README.md

@@ -60,6 +60,7 @@ possibility of automatically activating the `test` environment on all shells.
 | [Caching environments](#caching-environments)                      | [![Caching Env Example Status][caching-env-badge]][caching-env] |
 | [Apple Silicon](#example-13-apple-silicon)                         | [![Apple Silicon][ex13-badge]][ex13]                            |
 | [Remove defaults](#example-14-remove-defaults-channel)             | [![Remove defaults][ex14-badge]][ex14]                          |
+| [Linux ARM](#example-15-linux-arm)                                 | [![Linux ARM][ex15-badge]][ex15]                                |
 
 [ex1]:
   https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-1.yml
@@ -117,6 +118,10 @@ possibility of automatically activating the `test` environment on all shells.
   https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-14.yml
 [ex14-badge]:
   https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-14.yml/badge.svg?branch=main
+[ex15]:
+  https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-15.yml
+[ex15-badge]:
+  https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-15.yml/badge.svg?branch=main
 
 ## Other Workflows
 
@@ -598,7 +603,7 @@ jobs:
         id: setup-miniconda
         continue-on-error: true
         with:
-          miniconda-version: latest
+          miniforge-version: latest
       - name: Check arm64
         shell: bash -el {0}
         run: |
@@ -635,6 +640,31 @@ jobs:
           conda config --show-sources
 ```
 
+### Example 15: Linux ARM
+
+```yaml
+jobs:
+  example-15:
+    name: Ex15 (os=${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: ["ubuntu-24.04-arm"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./
+        id: setup-miniconda
+        continue-on-error: true
+        with:
+          miniforge-version: latest
+      - name: Check ARM
+        shell: bash -el {0}
+        run: |
+          conda install -y python
+          python -c "import platform; assert platform.machine() == 'aarch64', platform.machine()"
+```
+
 ## Caching
 
 ### Caching packages

src/constants.ts

@@ -31,9 +31,9 @@ export const MINICONDA_ARCHITECTURES: types.IArchitectures = {
 export const MINIFORGE_ARCHITECTURES: types.IArchitectures = {
   x64: "x86_64",
   x86_64: "x86_64",
-  aarch64: "aarch64", // To be supported by github runners
+  aarch64: "aarch64",
   ppc64le: "ppc64le", // To be supported by github runners
-  arm64: "arm64", // To be supported by github runners
+  arm64: "arm64",
 };
 
 export const OS_NAMES: types.IOperatingSystems = {

src/input.ts

@@ -79,9 +79,14 @@ const RULES: IRule[] = [
  * Parse, validate, and normalize string-ish inputs from a workflow action's `with`
  */
 export async function parseInputs(): Promise<types.IActionInputs> {
+  let arch = core.getInput("architecture") || process.arch;
+  if (arch === "arm64" && constants.IS_LINUX) {
+    // https://github.com/conda-incubator/setup-miniconda/issues/385
+    arch = "aarch64";
+  }
   const inputs: types.IActionInputs = Object.freeze({
     activateEnvironment: core.getInput("activate-environment"),
-    architecture: core.getInput("architecture") || process.arch,
+    architecture: arch,
     condaBuildVersion: core.getInput("conda-build-version"),
     condaConfigFile: core.getInput("condarc-file"),
     condaVersion: core.getInput("conda-version"),

src/installer/download-miniconda.ts

@@ -52,10 +52,6 @@ export async function downloadMiniconda(
   if (!arch) {
     throw new Error(`Invalid arch "${inputs.architecture}"!`);
   }
-  // Backwards compatibility: ARM64 used to map to aarch64
-  if (arch === "arm64" && constants.IS_LINUX) {
-    arch = constants.MINICONDA_ARCHITECTURES["aarch64"];
-  }
 
   let extension: string = constants.IS_UNIX ? "sh" : "exe";
   let osName: string = constants.OS_NAMES[process.platform];