Export SDKROOT environment variable.

.github/workflows/ci.yml

@@ -20,10 +20,10 @@ jobs:
           - macOS-26
         swift-version:
           - "6.2.1"
-          - DEVELOPMENT-SNAPSHOT-2025-09-07-a
+          - DEVELOPMENT-SNAPSHOT-2025-11-26-a
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install Swift.
         uses: ./
         with:
@@ -32,6 +32,8 @@ jobs:
         run: swift --version
       - name: Run Swift
         run: ./utils/swift-test
+      - name: Test clang
+        run: ./utils/clang-test
   branch-test-with-swift-version-file:
     name: Test with ".swift-version" file.
     strategy:
@@ -41,7 +43,7 @@ jobs:
           - macOS-26
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install Swift.
         uses: ./
         with:

.gitignore

@@ -3,6 +3,7 @@
 
 
 .DS_Store
+.vscode
 __pycache__
 *.pyc
 /node_modules/*

clang-test-source/test.c

@@ -0,0 +1,12 @@
+/* *************************************************************************************************
+ test.c
+   © 2025 YOCKOW.
+     Licensed under MIT License.
+     See "LICENSE.txt" for more information.
+ ************************************************************************************************ */
+
+#include <stdio.h>
+
+int main(int argc, char *argv[]){
+  printf("Hello, %s!\n", "World");
+}

lib/main.js

@@ -193,6 +193,16 @@ async function switch_swift(swift_version) {
             await run(`Switch Developer Directory to ${developerDirectory}`, async () => {
                 await exec.exec('sudo xcode-select', ['-switch', developerDirectory]);
             });
+            await run('Set SDKROOT environment variable', async () => {
+                await exec.exec('xcrun', ['--sdk', 'macosx', '--show-sdk-path'], {
+                    listeners: {
+                        stdout: (data) => {
+                            const sdkPath = data.toString().trim();
+                            core.exportVariable('SDKROOT', sdkPath);
+                        }
+                    }
+                });
+            });
         }
         core.addPath(swiftBinDirectory);
     });

src/main.ts

@@ -179,7 +179,21 @@ async function switch_swift(swift_version: string): Promise<void> {
       }
       await run(`Switch Developer Directory to ${developerDirectory}`, async () => {
         await exec.exec('sudo xcode-select', ['-switch', developerDirectory]);
-      })
+      });
+      await run('Set SDKROOT environment variable', async () => {
+        await exec.exec(
+          'xcrun',
+          ['--sdk', 'macosx', '--show-sdk-path'],
+          {
+            listeners: {
+              stdout: (data: Buffer) => {
+                const sdkPath = data.toString().trim();
+                core.exportVariable('SDKROOT', sdkPath);
+              }
+            }
+          }
+        )
+      });
     }
 
     core.addPath(swiftBinDirectory);

utils/clang-test

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+set -eu
+
+declare -r utilsDir="$(cd "$(dirname "$0")" && pwd -L)"
+declare -r repositoryDir="$(dirname "$utilsDir")"
+declare -r clangTestSourceDir="${repositoryDir}/clang-test-source"
+declare -r cTestSourcePath="${clangTestSourceDir}/test.c"
+
+cd $(mktemp -d)
+clang -O3 "$cTestSourcePath" -o ./test
+
+declare output; output="$(./test)"
+if [[ "$output" == "Hello, World!" ]]; then
+  echo "$output"
+else
+  echo "Unexpected output⁉: $output"
+  exit 1
+fi

utils/update-gitignore

@@ -7,6 +7,7 @@ from typing import List
 
 ignorables: List[str] = [
   '.DS_Store',
+  '.vscode',
   '__pycache__',
   '*.pyc',
   '/node_modules/*',