Mark Swift incompatible OS as configuration error

.github/workflows/debug-artifacts-failure-safe.yml

@@ -66,6 +66,7 @@ jobs:
         uses: ./../action/.github/actions/verify-debug-artifact-scan-completed
       - uses: ./../action/init
         with:
+          languages: cpp,csharp,go,java,javascript,python
           tools: ${{ steps.prepare-test.outputs.tools-url }}
           debug: true
           debug-artifact-name: my-debug-artifacts

pr-checks/checks/language-aliases.yml

@@ -5,12 +5,12 @@ versions:
 steps:
   - uses: ./../action/init
     with:
-      languages: C#,java-kotlin,swift,typescript
+      languages: C#,java-kotlin,typescript
       tools: ${{ steps.prepare-test.outputs.tools-url }}
 
   - name: "Check languages"
     run: |
-      expected_languages="csharp,java,swift,javascript"
+      expected_languages="csharp,java,javascript"
       actual_languages=$(jq -r '.languages | join(",")' "$RUNNER_TEMP"/config)
 
       if [ "$expected_languages" != "$actual_languages" ]; then

src/cli-errors.test.ts

@@ -299,6 +299,20 @@ test("wrapCliConfigurationError - swift build failed", (t) => {
   t.true(wrappedError instanceof ConfigurationError);
 });
 
+test("wrapCliConfigurationError - swift incompatible os", (t) => {
+  const commandError = new CommandInvocationError(
+    "codeql",
+    ["swift/tools/autobuild.sh"],
+    1,
+    "2026-04-01 18:35:00 EST ERRO [extractor/main] [incompatible-os] Currently, Swift analysis is only supported on macOS. (IncompatibleOs.cpp:26)",
+  );
+  const cliError = new CliError(commandError);
+
+  const wrappedError = wrapCliConfigurationError(cliError);
+
+  t.true(wrappedError instanceof ConfigurationError);
+});
+
 test("wrapCliConfigurationError - pack cannot be found", (t) => {
   const commandError = new CommandInvocationError(
     "codeql",

src/cli-errors.ts

@@ -144,6 +144,7 @@ export enum CliConfigErrorCategory {
   OutOfMemoryOrDisk = "OutOfMemoryOrDisk",
   PackCannotBeFound = "PackCannotBeFound",
   PackMissingAuth = "PackMissingAuth",
+  SwiftIncompatibleOs = "SwiftIncompatibleOs",
   SwiftBuildFailed = "SwiftBuildFailed",
   UnsupportedBuildMode = "UnsupportedBuildMode",
 }
@@ -281,6 +282,12 @@ const cliErrorsConfig: Record<CliConfigErrorCategory, CliErrorConfiguration> = {
       ),
     ],
   },
+  [CliConfigErrorCategory.SwiftIncompatibleOs]: {
+    cliErrorMessageCandidates: [
+      new RegExp("\\[incompatible-os\\]"),
+      new RegExp("Swift analysis is only supported on macOS"),
+    ],
+  },
   [CliConfigErrorCategory.UnsupportedBuildMode]: {
     cliErrorMessageCandidates: [
       new RegExp(

src/init-action.ts

@@ -389,6 +389,15 @@ async function run(startedAt: Date) {
       logger,
     });
 
+    if (
+      config.languages.includes(KnownLanguage.swift) &&
+      process.platform !== "darwin"
+    ) {
+      throw new ConfigurationError(
+        `Swift analysis is only supported on macOS runner images. Please migrate to a macOS runner.`,
+      );
+    }
+
     if (repositoryPropertiesResult.isFailure()) {
       addNoLanguageDiagnostic(
         config,
@@ -499,15 +508,6 @@ async function run(startedAt: Date) {
       );
     }
 
-    if (
-      config.languages.includes(KnownLanguage.swift) &&
-      process.platform === "linux"
-    ) {
-      logger.warning(
-        `Swift analysis on Ubuntu runner images is no longer supported. Please migrate to a macOS runner if this affects you.`,
-      );
-    }
-
     if (
       config.languages.includes(KnownLanguage.go) &&
       process.platform === "linux"