Add support for optional architecture input for cross-architecture .NET installs by priya-kinthali · Pull Request #700 · actions/setup-dotnet

priya-kinthali · 2026-02-23T14:26:37Z

Description:
This PR adds support for an optional architecture input that enables cross-architecture .NET SDK/runtime installations. Supported values: x64, x86, arm64, amd64, arm, s390x, ppc64le, riscv64. When not specified, the installer auto-detects the host architecture.

Related issue:
#524

Check list:

Mark if documentation changes are required.
Mark if tests were added or updated to cover the changes.

This reverts commit 27a0803.

Copilot

Pull request overview

Adds an optional architecture input to enable cross-architecture .NET SDK/runtime installation (e.g., installing x64 .NET on an arm64 runner), wiring the input through the installer, updating docs, and extending test coverage and e2e validation.

Changes:

Add architecture input parsing/validation and pass it into DotnetCoreInstaller.
Teach installer script invocation to pass --architecture/-Architecture and use a per-arch install directory for cross-arch installs.
Update action metadata/docs and add unit + e2e tests for the new input.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
`src/setup-dotnet.ts`	Parses `architecture`, forwards it to the installer, and adjusts PATH/DOTNET_ROOT for cross-arch installs.
`src/installer.ts`	Adds `useArchitecture()`, `normalizeArch()`, and cross-arch install-dir handling inside `DotnetCoreInstaller`.
`dist/setup/index.js`	Bundled output reflecting the new architecture support.
`action.yml`	Adds the `architecture` input to the action interface.
`__tests__/setup-dotnet.test.ts`	Adds unit tests for architecture input parsing/failure behavior.
`__tests__/installer.test.ts`	Adds unit tests ensuring architecture/install-dir flags are passed and tests `normalizeArch()`.
`README.md`	Documents the `architecture` input and provides an example.
`.github/workflows/e2e-tests.yml`	Adds an e2e job matrix to validate `architecture` usage across OSes.

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Copilot · 2026-02-23T14:34:17Z

src/installer.ts

+      normalizeArch(this.architecture) !== normalizeArch(os.arch())
+        ? IS_WINDOWS
+          ? [
+              `-InstallDir "${path.join(DotnetInstallDir.dirPath, this.architecture)}"`


On Windows, crossArchInstallDir builds -InstallDir "<path>" as a single argument string (including quotes). Since exec.getExecOutput receives an args array, the flag and value should be passed as separate array items (and without embedding quotes), otherwise the PowerShell script can receive an invalid -InstallDir value and cross-arch installs may fail.

Suggested change

`-InstallDir "${path.join(DotnetInstallDir.dirPath, this.architecture)}"`

'-InstallDir',

path.join(DotnetInstallDir.dirPath, this.architecture)

Copilot · 2026-02-23T14:34:18Z

src/installer.ts

+export function normalizeArch(arch: string): string {
+  switch (arch.toLowerCase()) {
+    case 'amd64':
+      return 'x64';


normalizeArch() only aliases amd64 -> x64. Node's os.arch() can return ia32 for 32-bit environments, which should likely be treated as x86; otherwise a native x86 install may be misdetected as cross-arch (affecting --install-dir/PATH/DOTNET_ROOT logic). Consider normalizing ia32 -> x86 (and any other Node arch aliases you rely on).

Suggested change

return 'x64';

return 'x64';

case 'ia32':

return 'x86';

Copilot · 2026-02-23T14:34:18Z

src/setup-dotnet.ts

+const supportedArchitectures = [
+  'x64',
+  'x86',
+  'arm64',
+  'amd64',
+  'arm',
+  's390x',
+  'ppc64le',
+  'riscv64'
+] as const;
+type SupportedArchitecture = (typeof supportedArchitectures)[number];



The supportedArchitectures allow-list includes values that the vendored install scripts don't support on all platforms (e.g. install-dotnet.sh does not accept x86 or riscv64, and install-dotnet.ps1 doesn't accept s390x/ppc64le/riscv64). This means the action can accept an input value but later fail inside the install script. The allow-list and error message should be platform-aware (or derived from the script capabilities) so validation matches actual supported values.

Suggested change

const supportedArchitectures = [

'x64',

'x86',

'arm64',

'amd64',

'arm',

's390x',

'ppc64le',

'riscv64'

] as const;

type SupportedArchitecture = (typeof supportedArchitectures)[number];

type SupportedArchitecture =

| 'x64'

| 'x86'

| 'arm64'

| 'amd64'

| 'arm'

| 's390x'

| 'ppc64le'

| 'riscv64';

function getSupportedArchitecturesForPlatform(

platform: NodeJS.Platform

): readonly SupportedArchitecture[] {

switch (platform) {

case 'win32':

// install-dotnet.ps1 does not support s390x, ppc64le, or riscv64

return ['x64', 'x86', 'arm64', 'arm'];

case 'linux':

// install-dotnet.sh does not support x86 or riscv64

return ['x64', 'arm64', 'arm', 's390x', 'ppc64le'];

case 'darwin':

// install-dotnet.sh on macOS does not support x86, s390x, ppc64le, or riscv64

return ['x64', 'arm64'];

default:

// Fallback to the full set of known architectures

return ['x64', 'x86', 'arm64', 'amd64', 'arm', 's390x', 'ppc64le', 'riscv64'];

}

}

const supportedArchitectures = getSupportedArchitecturesForPlatform(os.platform());

Copilot · 2026-02-23T14:34:19Z

action.yml

    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.'


The architecture input description lists values that aren't supported by the underlying install script on every OS (e.g. x86 isn't supported by install-dotnet.sh, and s390x/ppc64le/riscv64 aren't supported by install-dotnet.ps1). Since the action validates/advertises these values, please make the documented supported values platform-specific (or update validation/scripts so the statement is always true).

Suggested change

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.'

description: 'Optional architecture for the .NET install. Valid values depend on the operating system and install script, and can include x64/amd64, x86, arm64, arm, s390x, ppc64le, riscv64. If not set, the installer auto-detects the current system architecture.'

Copilot · 2026-02-23T14:34:19Z

README.md

+## 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>


This section states x86/riscv64 (and others) are valid architecture values and provides an x86 example, but the vendored externals/install-dotnet.sh doesn't support x86 (and doesn't list riscv64). Either adjust the docs/examples to match actual supported values per OS, or update the validation/install scripts so these architectures are truly supported.

priya-kinthali and others added 4 commits February 18, 2026 12:36

fix basic validation with npm command

27a0803

Revert "fix basic validation with npm command"

8aa3234

This reverts commit 27a0803.

Merge branch 'actions:main' into main

2f5efe9

add architecture support

f5b8fb7

Copilot AI review requested due to automatic review settings February 23, 2026 14:26

priya-kinthali requested a review from a team as a code owner February 23, 2026 14:26

Copilot started reviewing on behalf of priya-kinthali February 23, 2026 14:27 View session

Copilot AI reviewed Feb 23, 2026

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priya-kinthali self-assigned this Feb 23, 2026

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

Add support for optional architecture input for cross-architecture .NET installs#700
priya-kinthali wants to merge 4 commits intoactions:mainfrom
priya-kinthali:add-architecture-support

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	`-InstallDir "${path.join(DotnetInstallDir.dirPath, this.architecture)}"`
	'-InstallDir',
	path.join(DotnetInstallDir.dirPath, this.architecture)

-const supportedArchitectures = [
-  'x64',
-  'x86',
-  'arm64',
-  'amd64',
-  'arm',
-  's390x',
-  'ppc64le',
-  'riscv64'
-] as const;
-type SupportedArchitecture = (typeof supportedArchitectures)[number];
+type SupportedArchitecture =
+  | 'x64'
+  | 'x86'
+  | 'arm64'
+  | 'amd64'
+  | 'arm'
+  | 's390x'
+  | 'ppc64le'
+  | 'riscv64';
+function getSupportedArchitecturesForPlatform(
+  platform: NodeJS.Platform
+): readonly SupportedArchitecture[] {
+  switch (platform) {
+    case 'win32':
+      // install-dotnet.ps1 does not support s390x, ppc64le, or riscv64
+      return ['x64', 'x86', 'arm64', 'arm'];
+    case 'linux':
+      // install-dotnet.sh does not support x86 or riscv64
+      return ['x64', 'arm64', 'arm', 's390x', 'ppc64le'];
+    case 'darwin':
+      // install-dotnet.sh on macOS does not support x86, s390x, ppc64le, or riscv64
+      return ['x64', 'arm64'];
+    default:
+      // Fallback to the full set of known architectures
+      return ['x64', 'x86', 'arm64', 'amd64', 'arm', 's390x', 'ppc64le', 'riscv64'];
+  }
+}
+const supportedArchitectures = getSupportedArchitecturesForPlatform(os.platform());

	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.'
	description: 'Optional architecture for the .NET install. Valid values depend on the operating system and install script, and can include x64/amd64, x86, arm64, arm, s390x, ppc64le, riscv64. If not set, the installer auto-detects the current system architecture.'

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