erlef · gilbertbw · Jan 15, 2025 · Jan 15, 2025
diff --git a/README.md b/README.md
@@ -71,14 +71,14 @@ be the latest.
 This list presents the known working version combos between the target operating system
 and Erlang/OTP.
 
-| Operating system | Erlang/OTP  | Status
-|-                 |-            |-
-| `ubuntu-18.04`   | 17.0 - 25.3 | ✅
-| `ubuntu-20.04`   | 21.0 - 27   | ✅
-| `ubuntu-22.04`   | 24.2 - 27   | ✅
-| `ubuntu-24.04`   | 24.3 - 27   | ✅
-| `windows-2019`   | 21* - 25    | ✅
-| `windows-2022`   | 21* - 27    | ✅
+| Operating system | Erlang/OTP   | OTP Architecture | Status
+|-                 |-             |                  |-
+| `ubuntu-18.04`   | 17.0 - 25.3  | 32 bit           | ✅
+| `ubuntu-20.04`   | 21.0 - 27    | 32 bit           | ✅
+| `ubuntu-22.04`   | 24.2 - 27    | 32 bit           | ✅
+| `ubuntu-24.04`   | 24.3 - 27    | 32/64 bit        | ✅
+| `windows-2019`   | 21\* - 25    | 32/64 bit        | ✅
+| `windows-2022`   | 21\* - 27    | 32/64 bit        | ✅
 
 **Note** \*: prior to 23, Windows builds are only available for minor versions, e.g. 21.0, 21.3,
 22.0, etc.
@@ -194,6 +194,24 @@ jobs:
             https://cdn.jsdelivr.net/hex
 ```
 
+### OTP Architecture
+
+On Windows you can specify the OTP architecture to install.
+
+```yaml
+# create this in .github/workflows/ci.yml
+on: push
+
+jobs:
+  test:
+    runs-on: windows-latest
+    steps:
+      - uses: erlef/setup-beam@v1
+        with:
+          otp-version: '26'
+          otp-architecture: '32'
+```
+
 ### Environment variables
 
 Base installation folders (useful for e.g. fetching headers for NIFs) are available in the following

diff --git a/action.yml b/action.yml
@@ -19,6 +19,9 @@ inputs:
   otp-version:
     description: Version range or exact version of Erlang/OTP to use,
       or false when installing only Gleam without OTP
+  otp-architecture:
+    description: 32 or 64, to specify the architecture of the OTP to install. Only applies to Windows.
+    default: 64
   elixir-version:
     description: Version range or exact version of Elixir to use
   gleam-version:

diff --git a/dist/index.js b/dist/index.js
@@ -9119,6 +9119,7 @@ main().catch((err) => {
 
 async function main() {
   checkPlatform()
+  checkOtpArchitecture()
 
   const versionFilePath = getInput('version-file', false)
   let versions
@@ -9388,13 +9389,16 @@ async function getOTPVersions(osVersion) {
         otpVersions[otpVersion] = otpVersionOrig // we keep the original for later reference
       })
   } else if (process.platform === 'win32') {
+    const file_regex = new RegExp(
+      `^otp_win${getInput('otp-architecture')}_(.*).exe$`,
+    )
     otpVersionsListings.forEach((otpVersionsListing) => {
       otpVersionsListing
         .map((x) => x.assets)
         .flat()
-        .filter((x) => x.name.match(/^otp_win64_.*.exe$/))
+        .filter((x) => x.name.match(file_regex))
         .forEach((x) => {
-          const otpMatch = x.name.match(/^otp_win64_(.*).exe$/)
+          const otpMatch = x.name.match(file_regex)
           const otpVersion = otpMatch[1]
           debugLog('OTP line and parsing', [otpMatch, otpVersion])
           otpVersions[otpVersion] = otpVersion
@@ -9899,7 +9903,9 @@ async function install(toolName, opts) {
         win32: {
           downloadToolURL: () =>
             'https://github.com/erlang/otp/releases/download/' +
-            `OTP-${toolVersion}/otp_win64_${toolVersion}.exe`,
+            `OTP-${toolVersion}/otp_win${getInput(
+              'otp-architecture',
+            )}_${toolVersion}.exe`,
           extract: async () => ['file', 'otp.exe'],
           postExtract: async (cachePath) => {
             const cmd = path.join(cachePath, 'otp.exe')
@@ -10155,6 +10161,21 @@ function checkPlatform() {
   }
 }
 
+function checkOtpArchitecture() {
+  if (process.platform !== 'win32' && getInput('otp-architecture') == '32') {
+    throw new Error(
+      '@erlef/setup-beam only supports otp-architecture=32 on Windows',
+    )
+  }
+
+  if (
+    getInput('otp-architecture') !== '32' &&
+    getInput('otp-architecture') !== '64'
+  ) {
+    throw new Error('otp-architecture must be 32 or 64')
+  }
+}
+
 function debugLoggingEnabled() {
   return !!process.env.RUNNER_DEBUG
 }

diff --git a/src/setup-beam.js b/src/setup-beam.js
@@ -14,6 +14,7 @@ main().catch((err) => {
 
 async function main() {
   checkPlatform()
+  checkOtpArchitecture()
 
   const versionFilePath = getInput('version-file', false)
   let versions
@@ -288,13 +289,16 @@ async function getOTPVersions(osVersion) {
         otpVersions[otpVersion] = otpVersionOrig // we keep the original for later reference
       })
   } else if (process.platform === 'win32') {
+    const file_regex = new RegExp(
+      `^otp_win${getInput('otp-architecture')}_(.*).exe$`,
+    )
     otpVersionsListings.forEach((otpVersionsListing) => {
       otpVersionsListing
         .map((x) => x.assets)
         .flat()
-        .filter((x) => x.name.match(/^otp_win64_.*.exe$/))
+        .filter((x) => x.name.match(file_regex))
         .forEach((x) => {
-          const otpMatch = x.name.match(/^otp_win64_(.*).exe$/)
+          const otpMatch = x.name.match(file_regex)
           const otpVersion = otpMatch[1]
           debugLog('OTP line and parsing', [otpMatch, otpVersion])
           otpVersions[otpVersion] = otpVersion
@@ -799,7 +803,9 @@ async function install(toolName, opts) {
         win32: {
           downloadToolURL: () =>
             'https://github.com/erlang/otp/releases/download/' +
-            `OTP-${toolVersion}/otp_win64_${toolVersion}.exe`,
+            `OTP-${toolVersion}/otp_win${getInput(
+              'otp-architecture',
+            )}_${toolVersion}.exe`,
           extract: async () => ['file', 'otp.exe'],
           postExtract: async (cachePath) => {
             const cmd = path.join(cachePath, 'otp.exe')
@@ -1055,6 +1061,21 @@ function checkPlatform() {
   }
 }
 
+function checkOtpArchitecture() {
+  if (process.platform !== 'win32' && getInput('otp-architecture') == '32') {
+    throw new Error(
+      '@erlef/setup-beam only supports otp-architecture=32 on Windows',
+    )
+  }
+
+  if (
+    getInput('otp-architecture') !== '32' &&
+    getInput('otp-architecture') !== '64'
+  ) {
+    throw new Error('otp-architecture must be 32 or 64')
+  }
+}
+
 function debugLoggingEnabled() {
   return !!process.env.RUNNER_DEBUG
 }

diff --git a/test/setup-beam.test.js b/test/setup-beam.test.js
@@ -1,4 +1,5 @@
 simulateInput('otp-version', '25.1.2')
+simulateInput('otp-architecture', '64')
 simulateInput('elixir-version', '1.14.2')
 simulateInput('rebar3-version', '3.20')
 simulateInput('install-rebar', 'true')
@@ -283,6 +284,29 @@ async function testOTPVersions() {
     expected = '23.0.4'
     got = await setupBeam.getOTPVersion(spec, osVersion)
     assert.deepStrictEqual(got, expected)
+
+    // Check we get the same results for 32-bit OTP
+    before = simulateInput('otp-architecture', '32')
+
+    spec = '24.0.1'
+    osVersion = 'windows-latest'
+    expected = '24.0.1'
+    got = await setupBeam.getOTPVersion(spec, osVersion)
+    assert.deepStrictEqual(got, expected)
+
+    spec = '23.2.x'
+    osVersion = 'windows-2016'
+    expected = '23.2.7'
+    got = await setupBeam.getOTPVersion(spec, osVersion)
+    assert.deepStrictEqual(got, expected)
+
+    spec = '23.0'
+    osVersion = 'windows-2019'
+    expected = '23.0.4'
+    got = await setupBeam.getOTPVersion(spec, osVersion)
+    assert.deepStrictEqual(got, expected)
+
+    simulateInput('otp-architecture', before)
   }
 
   simulateInput('hexpm-mirrors', hexMirrors, { multiline: true })