Add support for optional architecture input for cross-architecture .NET installs (#700)

* fix basic validation with npm command

* Revert "fix basic validation with npm command"

This reverts commit 27a0803a2a.

* add architecture support

* updated installdir logic

* update architecture resolution

* update normalizeArch

.github/workflows/e2e-tests.yml

@@ -623,3 +623,38 @@ jobs:
       - name: Verify dotnet
         shell: pwsh
         run: __tests__/verify-dotnet.ps1 -Patterns "^9\.0"
+
+  test-setup-with-architecture-input:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, ubuntu-latest, windows-latest]
+        arch: [x64, arm64]
+        exclude:
+          - os: windows-latest
+            arch: arm64
+          - os: ubuntu-latest
+            arch: arm64
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Clear toolcache
+        shell: pwsh
+        run: __tests__/clear-toolcache.ps1 ${{ runner.os }}
+
+      - name: Setup dotnet (${{ matrix.arch }})
+        uses: ./
+        with:
+          dotnet-version: |
+            8.0.416
+            8.0.x
+            9.0.308
+            10.0.101
+          architecture: ${{ matrix.arch }}
+
+      - name: Verify dotnet
+        shell: pwsh
+        run: __tests__/verify-dotnet.ps1 -Patterns "^8.0.416$", "^9.0.308$", "^10.0.101$", "^8.0"

README.md

@@ -59,6 +59,23 @@ The `dotnet-version` input supports following syntax:
 - **A.B.Cxx** (e.g. 8.0.4xx) - available since `.NET 5.0` release. Installs the latest version of the specific SDK release, including prerelease versions (preview, rc). 
 
 
+## Using the `architecture` input
+Using the architecture input, it is possible to specify the required .NET SDK architecture. Possible values:  `x64`, `x86`, `arm64`, `amd64`, `arm`, `s390x`, `ppc64le`, `riscv64`. If the input is not specified, the architecture defaults to the host OS architecture (not all of the architectures are available on all platforms).
+
+**Example: Install multiple SDK versions for a specific architecture**
+```yml
+steps:
+- uses: actions/checkout@v6
+- name: Setup dotnet (x86)
+  uses: actions/setup-dotnet@v5
+  with:
+    dotnet-version: |
+      8.0.x
+      9.0.x
+    architecture: x86
+- run: dotnet build <my project>
+```
+
 ## Using the `dotnet-quality` input
 This input sets up the action to install the latest build of the specified quality in the channel. The possible values of `dotnet-quality` are: **daily**, **signed**, **validated**, **preview**, **ga**.
 

__tests__/installer.test.ts

@@ -2,6 +2,7 @@ import each from 'jest-each';
 import semver from 'semver';
 import fs from 'fs';
 import fspromises from 'fs/promises';
+import os from 'os';
 import * as exec from '@actions/exec';
 import * as core from '@actions/core';
 import * as io from '@actions/io';
@@ -327,6 +328,143 @@ describe('installer tests', () => {
           );
         });
       }
+
+      it(`should supply 'architecture' argument to the installation script when architecture is provided`, async () => {
+        const inputVersion = '10.0.101';
+        const inputQuality = '' as QualityOptions;
+        const inputArchitecture = 'x64';
+        const stdout = `Fictitious dotnet version ${inputVersion} is installed`;
+
+        getExecOutputSpy.mockImplementation(() => {
+          return Promise.resolve({
+            exitCode: 0,
+            stdout: `${stdout}`,
+            stderr: ''
+          });
+        });
+        maxSatisfyingSpy.mockImplementation(() => inputVersion);
+
+        const dotnetInstaller = new installer.DotnetCoreInstaller(
+          inputVersion,
+          inputQuality,
+          inputArchitecture
+        );
+
+        await dotnetInstaller.installDotnet();
+
+        const callIndex = 1;
+        const scriptArguments = (
+          getExecOutputSpy.mock.calls[callIndex][1] as string[]
+        ).join(' ');
+        const expectedArgument = IS_WINDOWS
+          ? `-Architecture ${inputArchitecture}`
+          : `--architecture ${inputArchitecture}`;
+
+        expect(scriptArguments).toContain(expectedArgument);
+      });
+
+      it(`should NOT supply 'architecture' argument when architecture is not provided`, async () => {
+        const inputVersion = '10.0.101';
+        const inputQuality = '' as QualityOptions;
+        const stdout = `Fictitious dotnet version ${inputVersion} is installed`;
+
+        getExecOutputSpy.mockImplementation(() => {
+          return Promise.resolve({
+            exitCode: 0,
+            stdout: `${stdout}`,
+            stderr: ''
+          });
+        });
+        maxSatisfyingSpy.mockImplementation(() => inputVersion);
+
+        const dotnetInstaller = new installer.DotnetCoreInstaller(
+          inputVersion,
+          inputQuality
+        );
+
+        await dotnetInstaller.installDotnet();
+
+        const callIndex = 1;
+        const scriptArguments = (
+          getExecOutputSpy.mock.calls[callIndex][1] as string[]
+        ).join(' ');
+
+        expect(scriptArguments).not.toContain('--architecture');
+        expect(scriptArguments).not.toContain('-Architecture');
+      });
+
+      it(`should supply 'install-dir' with arch subdirectory for cross-arch install`, async () => {
+        const inputVersion = '10.0.101';
+        const inputQuality = '' as QualityOptions;
+        const inputArchitecture = 'x64';
+        const stdout = `Fictitious dotnet version ${inputVersion} is installed`;
+
+        getExecOutputSpy.mockImplementation(() => {
+          return Promise.resolve({
+            exitCode: 0,
+            stdout: `${stdout}`,
+            stderr: ''
+          });
+        });
+        maxSatisfyingSpy.mockImplementation(() => inputVersion);
+
+        // Mock os.arch() to return a different arch to simulate cross-arch
+        const archSpy = jest.spyOn(os, 'arch').mockReturnValue('arm64');
+
+        const dotnetInstaller = new installer.DotnetCoreInstaller(
+          inputVersion,
+          inputQuality,
+          inputArchitecture
+        );
+
+        await dotnetInstaller.installDotnet();
+
+        const callIndex = 1;
+        const scriptArguments = (
+          getExecOutputSpy.mock.calls[callIndex][1] as string[]
+        ).join(' ');
+
+        const expectedInstallDirFlag = IS_WINDOWS
+          ? '-InstallDir'
+          : '--install-dir';
+
+        expect(scriptArguments).toContain(expectedInstallDirFlag);
+        expect(scriptArguments).toContain(inputArchitecture);
+
+        archSpy.mockRestore();
+      });
+
+      it(`should NOT supply 'install-dir' when architecture matches runner's native arch`, async () => {
+        const inputVersion = '10.0.101';
+        const inputQuality = '' as QualityOptions;
+        const nativeArch = os.arch().toLowerCase();
+        const stdout = `Fictitious dotnet version ${inputVersion} is installed`;
+
+        getExecOutputSpy.mockImplementation(() => {
+          return Promise.resolve({
+            exitCode: 0,
+            stdout: `${stdout}`,
+            stderr: ''
+          });
+        });
+        maxSatisfyingSpy.mockImplementation(() => inputVersion);
+
+        const dotnetInstaller = new installer.DotnetCoreInstaller(
+          inputVersion,
+          inputQuality,
+          nativeArch
+        );
+
+        await dotnetInstaller.installDotnet();
+
+        const callIndex = 1;
+        const scriptArguments = (
+          getExecOutputSpy.mock.calls[callIndex][1] as string[]
+        ).join(' ');
+
+        expect(scriptArguments).not.toContain('--install-dir');
+        expect(scriptArguments).not.toContain('-InstallDir');
+      });
     });
 
     describe('addToPath() tests', () => {
@@ -346,6 +484,32 @@ describe('installer tests', () => {
     });
   });
 
+  describe('normalizeArch() tests', () => {
+    it(`should normalize 'amd64' to 'x64'`, () => {
+      expect(installer.normalizeArch('amd64')).toBe('x64');
+    });
+
+    it(`should normalize 'AMD64' to 'x64' (case-insensitive)`, () => {
+      expect(installer.normalizeArch('AMD64')).toBe('x64');
+    });
+
+    it(`should pass through 'x64' unchanged`, () => {
+      expect(installer.normalizeArch('x64')).toBe('x64');
+    });
+
+    it(`should pass through 'arm64' unchanged`, () => {
+      expect(installer.normalizeArch('arm64')).toBe('arm64');
+    });
+
+    it(`should lowercase 'ARM64'`, () => {
+      expect(installer.normalizeArch('ARM64')).toBe('arm64');
+    });
+
+    it(`should pass through 'x86' unchanged`, () => {
+      expect(installer.normalizeArch('x86')).toBe('x86');
+    });
+  });
+
   describe('DotnetVersionResolver tests', () => {
     describe('createDotnetVersion() tests', () => {
       each([

__tests__/setup-dotnet.test.ts

@@ -2,7 +2,7 @@ import * as core from '@actions/core';
 import fs from 'fs';
 import semver from 'semver';
 import * as auth from '../src/authutil';
-
+import os from 'os';
 import * as setup from '../src/setup-dotnet';
 import {DotnetCoreInstaller, DotnetInstallDir} from '../src/installer';
 import * as cacheUtils from '../src/cache-utils';
@@ -221,5 +221,40 @@ describe('setup-dotnet tests', () => {
       await setup.run();
       expect(restoreCacheSpy).not.toHaveBeenCalled();
     });
+
+    it('should pass valid architecture input to DotnetCoreInstaller', async () => {
+      inputs['dotnet-version'] = ['10.0.101'];
+      inputs['dotnet-quality'] = '';
+      inputs['architecture'] = os.arch().toLowerCase();
+
+      installDotnetSpy.mockImplementation(() => Promise.resolve(''));
+
+      await setup.run();
+      expect(installDotnetSpy).toHaveBeenCalledTimes(1);
+      expect(DotnetInstallDir.addToPath).toHaveBeenCalledTimes(1);
+    });
+
+    it('should work with empty architecture input for auto-detection', async () => {
+      inputs['dotnet-version'] = ['10.0.101'];
+      inputs['dotnet-quality'] = '';
+      inputs['architecture'] = '';
+
+      installDotnetSpy.mockImplementation(() => Promise.resolve(''));
+
+      await setup.run();
+      expect(installDotnetSpy).toHaveBeenCalledTimes(1);
+      expect(DotnetInstallDir.addToPath).toHaveBeenCalledTimes(1);
+    });
+
+    it('should fail the action if unsupported architecture is provided', async () => {
+      inputs['dotnet-version'] = ['10.0.101'];
+      inputs['dotnet-quality'] = '';
+      inputs['architecture'] = 'x688';
+
+      const expectedErrorMessage = `Value 'x688' is not supported for the 'architecture' option. Supported values are: x64, x86, arm64, amd64, arm, s390x, ppc64le, riscv64.`;
+
+      await setup.run();
+      expect(setFailedSpy).toHaveBeenCalledWith(expectedErrorMessage);
+    });
   });
 });

action.yml

@@ -27,6 +27,9 @@ inputs:
   workloads:
     description: 'Optional SDK workloads to install for additional platform support. Examples: wasm-tools, maui, aspire.'
     required: false
+  architecture:
+    description: 'Optional architecture for the .NET install. Supported values: x64, x86, arm64, amd64, arm, s390x, ppc64le, riscv64. If not set, the installer auto-detects the current system architecture.'
+    required: false
 outputs:
   cache-hit:
     description: 'A boolean value to indicate if a cache was hit.'

dist/setup/index.js

@@ -54714,6 +54714,7 @@ var __importDefault = (this && this.__importDefault) || function (mod) {
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.DotnetCoreInstaller = exports.DotnetInstallDir = exports.DotnetInstallScript = exports.DotnetVersionResolver = void 0;
+exports.normalizeArch = normalizeArch;
 // Load tempDirectory before it gets wiped by tool-cache
 const core = __importStar(__nccwpck_require__(42186));
 const exec = __importStar(__nccwpck_require__(71514));
@@ -54859,6 +54860,13 @@ class DotnetInstallScript {
         this.scriptArguments.push(...args);
         return this;
     }
+    // When architecture is empty/undefined, the installer auto-detects the current runner architecture.
+    useArchitecture(architecture) {
+        if (!architecture)
+            return this;
+        this.useArguments(utils_1.IS_WINDOWS ? '-Architecture' : '--architecture', architecture);
+        return this;
+    }
     useVersion(dotnetVersion, quality) {
         if (dotnetVersion.type) {
             this.useArguments(dotnetVersion.type, dotnetVersion.value);
@@ -54907,30 +54915,53 @@ class DotnetInstallDir {
     }
 }
 exports.DotnetInstallDir = DotnetInstallDir;
+function normalizeArch(arch) {
+    switch (arch.toLowerCase()) {
+        case 'amd64':
+            return 'x64';
+        case 'ia32':
+            return 'x86';
+        default:
+            return arch.toLowerCase();
+    }
+}
 class DotnetCoreInstaller {
     version;
     quality;
+    architecture;
     static {
         DotnetInstallDir.setEnvironmentVariable();
     }
-    constructor(version, quality) {
+    constructor(version, quality, architecture) {
         this.version = version;
         this.quality = quality;
+        this.architecture = architecture;
     }
     async installDotnet() {
         const versionResolver = new DotnetVersionResolver(this.version);
         const dotnetVersion = await versionResolver.createDotnetVersion();
+        const architectureArguments = this.architecture &&
+            normalizeArch(this.architecture) !== normalizeArch(os_1.default.arch())
+            ? [
+                utils_1.IS_WINDOWS ? '-InstallDir' : '--install-dir',
+                utils_1.IS_WINDOWS
+                    ? `"${path_1.default.join(DotnetInstallDir.dirPath, this.architecture)}"`
+                    : path_1.default.join(DotnetInstallDir.dirPath, this.architecture)
+            ]
+            : [];
         /**
-         * Install dotnet runitme first in order to get
+         * Install dotnet runtime first in order to get
          * the latest stable version of dotnet CLI
          */
         const runtimeInstallOutput = await new DotnetInstallScript()
+            .useArchitecture(this.architecture)
             // If dotnet CLI is already installed - avoid overwriting it
             .useArguments(utils_1.IS_WINDOWS ? '-SkipNonVersionedFiles' : '--skip-non-versioned-files')
             // Install only runtime + CLI
             .useArguments(utils_1.IS_WINDOWS ? '-Runtime' : '--runtime', 'dotnet')
             // Use latest stable version
             .useArguments(utils_1.IS_WINDOWS ? '-Channel' : '--channel', 'LTS')
+            .useArguments(...architectureArguments)
             .execute();
         if (runtimeInstallOutput.exitCode) {
             /**
@@ -54944,10 +54975,12 @@ class DotnetCoreInstaller {
          * dotnet CLI
          */
         const dotnetInstallOutput = await new DotnetInstallScript()
+            .useArchitecture(this.architecture)
             // Don't overwrite CLI because it should be already installed
             .useArguments(utils_1.IS_WINDOWS ? '-SkipNonVersionedFiles' : '--skip-non-versioned-files')
             // Use version provided by user
             .useVersion(dotnetVersion, this.quality)
+            .useArguments(...architectureArguments)
             .execute();
         if (dotnetInstallOutput.exitCode) {
             throw new Error(`Failed to install dotnet, exit code: ${dotnetInstallOutput.exitCode}. ${dotnetInstallOutput.stderr}`);
@@ -55018,6 +55051,7 @@ const installer_1 = __nccwpck_require__(12574);
 const fs = __importStar(__nccwpck_require__(57147));
 const path_1 = __importDefault(__nccwpck_require__(71017));
 const semver_1 = __importDefault(__nccwpck_require__(11383));
+const os_1 = __importDefault(__nccwpck_require__(22037));
 const auth = __importStar(__nccwpck_require__(17573));
 const cache_utils_1 = __nccwpck_require__(41678);
 const cache_restore_1 = __nccwpck_require__(19517);
@@ -55030,6 +55064,16 @@ const qualityOptions = [
     'preview',
     'ga'
 ];
+const supportedArchitectures = [
+    'x64',
+    'x86',
+    'arm64',
+    'amd64',
+    'arm',
+    's390x',
+    'ppc64le',
+    'riscv64'
+];
 async function run() {
     try {
         //
@@ -55043,6 +55087,7 @@ async function run() {
         //
         const versions = core.getMultilineInput('dotnet-version');
         const installedDotnetVersions = [];
+        const architecture = getArchitectureInput();
         const globalJsonFileInput = core.getInput('global-json-file');
         if (globalJsonFileInput) {
             const globalJsonPath = path_1.default.resolve(process.cwd(), globalJsonFileInput);
@@ -55070,10 +55115,14 @@ async function run() {
             let dotnetInstaller;
             const uniqueVersions = new Set(versions);
             for (const version of uniqueVersions) {
-                dotnetInstaller = new installer_1.DotnetCoreInstaller(version, quality);
+                dotnetInstaller = new installer_1.DotnetCoreInstaller(version, quality, architecture);
                 const installedVersion = await dotnetInstaller.installDotnet();
                 installedDotnetVersions.push(installedVersion);
             }
+            if (architecture &&
+                (0, installer_1.normalizeArch)(architecture) !== (0, installer_1.normalizeArch)(os_1.default.arch())) {
+                process.env['DOTNET_INSTALL_DIR'] = path_1.default.join(installer_1.DotnetInstallDir.dirPath, architecture);
+            }
             installer_1.DotnetInstallDir.addToPath();
             const workloadsInput = core.getInput('workloads');
             if (workloadsInput) {
@@ -55111,6 +55160,16 @@ async function run() {
         core.setFailed(error.message);
     }
 }
+function getArchitectureInput() {
+    const raw = (core.getInput('architecture') || '').trim();
+    if (!raw)
+        return '';
+    const normalized = raw.toLowerCase();
+    if (supportedArchitectures.includes(normalized)) {
+        return (0, installer_1.normalizeArch)(normalized);
+    }
+    throw new Error(`Value '${raw}' is not supported for the 'architecture' option. Supported values are: ${supportedArchitectures.join(', ')}.`);
+}
 function getVersionFromGlobalJson(globalJsonPath) {
     let version = '';
     const globalJson = json5_1.default.parse(

src/installer.ts

@@ -184,6 +184,16 @@ export class DotnetInstallScript {
     return this;
   }
 
+  // When architecture is empty/undefined, the installer auto-detects the current runner architecture.
+  public useArchitecture(architecture?: string) {
+    if (!architecture) return this;
+    this.useArguments(
+      IS_WINDOWS ? '-Architecture' : '--architecture',
+      architecture
+    );
+    return this;
+  }
+
   public useVersion(dotnetVersion: DotnetVersion, quality?: QualityOptions) {
     if (dotnetVersion.type) {
       this.useArguments(dotnetVersion.type, dotnetVersion.value);
@@ -250,6 +260,17 @@ export abstract class DotnetInstallDir {
   }
 }
 
+export function normalizeArch(arch: string): string {
+  switch (arch.toLowerCase()) {
+    case 'amd64':
+      return 'x64';
+    case 'ia32':
+      return 'x86';
+    default:
+      return arch.toLowerCase();
+  }
+}
+
 export class DotnetCoreInstaller {
   static {
     DotnetInstallDir.setEnvironmentVariable();
@@ -257,18 +278,30 @@ export class DotnetCoreInstaller {
 
   constructor(
     private version: string,
-    private quality: QualityOptions
+    private quality: QualityOptions,
+    private architecture?: string
   ) {}
 
   public async installDotnet(): Promise<string | null> {
     const versionResolver = new DotnetVersionResolver(this.version);
     const dotnetVersion = await versionResolver.createDotnetVersion();
 
+    const architectureArguments =
+      this.architecture &&
+      normalizeArch(this.architecture) !== normalizeArch(os.arch())
+        ? [
+            IS_WINDOWS ? '-InstallDir' : '--install-dir',
+            IS_WINDOWS
+              ? `"${path.join(DotnetInstallDir.dirPath, this.architecture)}"`
+              : path.join(DotnetInstallDir.dirPath, this.architecture)
+          ]
+        : [];
     /**
-     * Install dotnet runitme first in order to get
+     * Install dotnet runtime first in order to get
      * the latest stable version of dotnet CLI
      */
     const runtimeInstallOutput = await new DotnetInstallScript()
+      .useArchitecture(this.architecture)
       // If dotnet CLI is already installed - avoid overwriting it
       .useArguments(
         IS_WINDOWS ? '-SkipNonVersionedFiles' : '--skip-non-versioned-files'
@@ -277,6 +310,7 @@ export class DotnetCoreInstaller {
       .useArguments(IS_WINDOWS ? '-Runtime' : '--runtime', 'dotnet')
       // Use latest stable version
       .useArguments(IS_WINDOWS ? '-Channel' : '--channel', 'LTS')
+      .useArguments(...architectureArguments)
       .execute();
 
     if (runtimeInstallOutput.exitCode) {
@@ -294,12 +328,14 @@ export class DotnetCoreInstaller {
      * dotnet CLI
      */
     const dotnetInstallOutput = await new DotnetInstallScript()
+      .useArchitecture(this.architecture)
       // Don't overwrite CLI because it should be already installed
       .useArguments(
         IS_WINDOWS ? '-SkipNonVersionedFiles' : '--skip-non-versioned-files'
       )
       // Use version provided by user
       .useVersion(dotnetVersion, this.quality)
+      .useArguments(...architectureArguments)
       .execute();
 
     if (dotnetInstallOutput.exitCode) {

src/setup-dotnet.ts

@@ -1,9 +1,14 @@
 import * as core from '@actions/core';
 import * as exec from '@actions/exec';
-import {DotnetCoreInstaller, DotnetInstallDir} from './installer';
+import {
+  DotnetCoreInstaller,
+  DotnetInstallDir,
+  normalizeArch
+} from './installer';
 import * as fs from 'fs';
 import path from 'path';
 import semver from 'semver';
+import os from 'os';
 import * as auth from './authutil';
 import {isCacheFeatureAvailable} from './cache-utils';
 import {restoreCache} from './cache-restore';
@@ -17,6 +22,17 @@ const qualityOptions = [
   'preview',
   'ga'
 ] as const;
+const supportedArchitectures = [
+  'x64',
+  'x86',
+  'arm64',
+  'amd64',
+  'arm',
+  's390x',
+  'ppc64le',
+  'riscv64'
+] as const;
+type SupportedArchitecture = (typeof supportedArchitectures)[number];
 
 export type QualityOptions = (typeof qualityOptions)[number];
 
@@ -33,6 +49,7 @@ export async function run() {
     //
     const versions = core.getMultilineInput('dotnet-version');
     const installedDotnetVersions: (string | null)[] = [];
+    const architecture = getArchitectureInput();
 
     const globalJsonFileInput = core.getInput('global-json-file');
     if (globalJsonFileInput) {
@@ -70,10 +87,23 @@ export async function run() {
       let dotnetInstaller: DotnetCoreInstaller;
       const uniqueVersions = new Set<string>(versions);
       for (const version of uniqueVersions) {
-        dotnetInstaller = new DotnetCoreInstaller(version, quality);
+        dotnetInstaller = new DotnetCoreInstaller(
+          version,
+          quality,
+          architecture
+        );
         const installedVersion = await dotnetInstaller.installDotnet();
         installedDotnetVersions.push(installedVersion);
       }
+      if (
+        architecture &&
+        normalizeArch(architecture) !== normalizeArch(os.arch())
+      ) {
+        process.env['DOTNET_INSTALL_DIR'] = path.join(
+          DotnetInstallDir.dirPath,
+          architecture
+        );
+      }
       DotnetInstallDir.addToPath();
 
       const workloadsInput = core.getInput('workloads');
@@ -119,6 +149,20 @@ export async function run() {
   }
 }
 
+function getArchitectureInput(): SupportedArchitecture | '' {
+  const raw = (core.getInput('architecture') || '').trim();
+  if (!raw) return '';
+  const normalized = raw.toLowerCase();
+  if ((supportedArchitectures as readonly string[]).includes(normalized)) {
+    return normalizeArch(normalized) as SupportedArchitecture;
+  }
+  throw new Error(
+    `Value '${raw}' is not supported for the 'architecture' option. Supported values are: ${supportedArchitectures.join(
+      ', '
+    )}.`
+  );
+}
+
 function getVersionFromGlobalJson(globalJsonPath: string): string {
   let version = '';
   const globalJson = JSON5.parse(