Add FF to force JGit-based Git backend

CHANGELOG.md

@@ -6,10 +6,6 @@ See the [releases page](https://github.com/github/codeql-action/releases) for th
 
 No user facing changes.
 
-## 4.36.1 - 02 Jun 2026
-
-No user facing changes.
-
 ## 4.36.0 - 22 May 2026
 
 - _Breaking change_: Bump the minimum required CodeQL bundle version to 2.19.4. [#3894](https://github.com/github/codeql-action/pull/3894)

lib/entry-points.js

@@ -148366,7 +148366,7 @@ function getDiffRangesJsonFilePath() {
   return path2.join(getTemporaryDirectory(), PR_DIFF_RANGE_JSON_FILENAME);
 }
 function getActionVersion() {
-  return "4.36.2";
+  return "4.36.1";
 }
 function getWorkflowEventName() {
   return getRequiredEnvParam("GITHUB_EVENT_NAME");
@@ -149396,6 +149396,11 @@ var featureConfig = {
     legacyApi: true,
     minimumVersion: void 0
   },
+  ["force_jgit" /* ForceJGit */]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_FORCE_JGIT",
+    minimumVersion: void 0
+  },
   ["force_nightly" /* ForceNightly */]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_FORCE_NIGHTLY",
@@ -151711,7 +151716,6 @@ async function initActionState({
     extraQueryExclusions: [],
     overlayDatabaseMode: "none" /* None */,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: false,
     repositoryProperties,
     enableFileCoverageInformation
   };
@@ -151840,7 +151844,6 @@ async function checkOverlayEnablement(codeql, features, languages, sourceRoot, b
     return validateOverlayDatabaseMode(
       modeEnv,
       false,
-      true,
       codeql,
       languages,
       sourceRoot,
@@ -151915,7 +151918,6 @@ async function checkOverlayEnablement(codeql, features, languages, sourceRoot, b
   return validateOverlayDatabaseMode(
     overlayDatabaseMode,
     true,
-    false,
     codeql,
     languages,
     sourceRoot,
@@ -151924,7 +151926,7 @@ async function checkOverlayEnablement(codeql, features, languages, sourceRoot, b
     logger
   );
 }
-async function validateOverlayDatabaseMode(overlayDatabaseMode, useOverlayDatabaseCaching, overlayModeSetExplicitly, codeql, languages, sourceRoot, buildMode, gitVersion, logger) {
+async function validateOverlayDatabaseMode(overlayDatabaseMode, useOverlayDatabaseCaching, codeql, languages, sourceRoot, buildMode, gitVersion, logger) {
   if (buildMode !== "none" /* None */ && (await Promise.all(
     languages.map(
       async (l) => l !== "go" /* go */ && // Workaround to allow overlay analysis for Go with any build
@@ -151968,8 +151970,7 @@ async function validateOverlayDatabaseMode(overlayDatabaseMode, useOverlayDataba
   }
   return new Success({
     overlayDatabaseMode,
-    useOverlayDatabaseCaching,
+    useOverlayDatabaseCaching
-    overlayModeSetExplicitly
   });
 }
 async function isTrapCachingEnabled(features, overlayDatabaseMode) {
@@ -152007,7 +152008,7 @@ function hasQueryCustomisation(userConfig) {
   return isDefined2(userConfig["disable-default-queries"]) || isDefined2(userConfig.queries) || isDefined2(userConfig["query-filters"]);
 }
 async function applyIncrementalAnalysisSettings(config, hasDiffRanges, codeql, logger) {
-  if (config.overlayDatabaseMode === "overlay" /* Overlay */ && !hasDiffRanges && !config.overlayModeSetExplicitly) {
+  if (config.overlayDatabaseMode === "overlay" /* Overlay */ && !hasDiffRanges) {
     logger.info(
       `Reverting overlay database mode to ${"none" /* None */} because the PR diff ranges could not be computed.`
     );
@@ -152115,17 +152116,12 @@ async function initConfig(features, inputs) {
     logger
   );
   if (overlayDatabaseModeResult.isSuccess()) {
-    const {
+    const { overlayDatabaseMode, useOverlayDatabaseCaching } = overlayDatabaseModeResult.value;
-      overlayDatabaseMode,
-      useOverlayDatabaseCaching,
-      overlayModeSetExplicitly
-    } = overlayDatabaseModeResult.value;
     logger.info(
       `Using overlay database mode: ${overlayDatabaseMode} ${useOverlayDatabaseCaching ? "with" : "without"} caching.`
     );
     config.overlayDatabaseMode = overlayDatabaseMode;
     config.useOverlayDatabaseCaching = useOverlayDatabaseCaching;
-    config.overlayModeSetExplicitly = overlayModeSetExplicitly;
   } else {
     const overlayDisabledReason = overlayDatabaseModeResult.value;
     logger.info(
@@ -159357,6 +159353,9 @@ exec ${goBinaryPath} "$@"`
     if (await features.getValue("disable_kotlin_analysis_enabled" /* DisableKotlinAnalysisEnabled */)) {
       core21.exportVariable("CODEQL_EXTRACTOR_JAVA_AGENT_DISABLE_KOTLIN", "true");
     }
+    if (await features.getValue("force_jgit" /* ForceJGit */)) {
+      core21.exportVariable("CODEQL_GIT_BACKEND", "jgit");
+    }
     const kotlinLimitVar = "CODEQL_EXTRACTOR_KOTLIN_OVERRIDE_MAXIMUM_VERSION_LIMIT";
     if (await codeQlVersionAtLeast(codeql, "2.20.3") && !await codeQlVersionAtLeast(codeql, "2.20.4")) {
       core21.exportVariable(kotlinLimitVar, "2.1.20");

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "codeql",
-  "version": "4.36.2",
+  "version": "4.36.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "codeql",
-      "version": "4.36.2",
+      "version": "4.36.1",
       "license": "MIT",
       "workspaces": [
         "pr-checks"

package.json

@@ -1,6 +1,6 @@
 {
   "name": "codeql",
-  "version": "4.36.2",
+  "version": "4.36.1",
   "private": true,
   "description": "CodeQL action",
   "scripts": {

src/config-utils.test.ts

@@ -1044,7 +1044,6 @@ const checkOverlayEnablementMacro = makeMacro({
       | {
           overlayDatabaseMode: OverlayDatabaseMode;
           useOverlayDatabaseCaching: boolean;
-          overlayModeSetExplicitly?: boolean;
         }
       | {
           disabledReason: OverlayDisabledReason;
@@ -1125,13 +1124,7 @@ const checkOverlayEnablementMacro = makeMacro({
         if ("disabledReason" in expected) {
           t.deepEqual(result, new Failure(expected.disabledReason));
         } else {
-          t.deepEqual(
+          t.deepEqual(result, new Success(expected));
-            result,
-            new Success({
-              overlayModeSetExplicitly: false,
-              ...expected,
-            }),
-          );
         }
       } finally {
         // Restore the original environment
@@ -1150,7 +1143,6 @@ checkOverlayEnablementMacro.serial(
   {
     overlayDatabaseMode: OverlayDatabaseMode.Overlay,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: true,
   },
 );
 
@@ -1162,7 +1154,6 @@ checkOverlayEnablementMacro.serial(
   {
     overlayDatabaseMode: OverlayDatabaseMode.OverlayBase,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: true,
   },
 );
 
@@ -1821,7 +1812,6 @@ checkOverlayEnablementMacro.serial(
   {
     overlayDatabaseMode: OverlayDatabaseMode.Overlay,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: true,
   },
 );
 
@@ -1834,7 +1824,6 @@ checkOverlayEnablementMacro.serial(
   {
     overlayDatabaseMode: OverlayDatabaseMode.Overlay,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: true,
   },
 );
 
@@ -1931,7 +1920,6 @@ checkOverlayEnablementMacro.serial(
   {
     overlayDatabaseMode: OverlayDatabaseMode.Overlay,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: true,
   },
 );
 
@@ -1977,7 +1965,6 @@ checkOverlayEnablementMacro.serial(
   {
     overlayDatabaseMode: OverlayDatabaseMode.Overlay,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: true,
   },
 );
 
@@ -2195,64 +2182,33 @@ test("applyIncrementalAnalysisSettings: keeps overlay mode and adds exclusions w
   ]);
 });
 
-test.serial(
+test("applyIncrementalAnalysisSettings: disables overlay analysis when diff ranges are unavailable", async (t) => {
-  "applyIncrementalAnalysisSettings: disables overlay analysis when diff ranges are unavailable",
+  const config = createTestConfig({
-  async (t) => {
+    overlayDatabaseMode: OverlayDatabaseMode.Overlay,
-    const config = createTestConfig({
+  });
-      overlayDatabaseMode: OverlayDatabaseMode.Overlay,
+  config.useOverlayDatabaseCaching = true;
-    });
+  const codeql = createStubCodeQL({});
-    config.useOverlayDatabaseCaching = true;
+  const logger = getRunnerLogger(true);
-    const codeql = createStubCodeQL({});
+  const addDiagnosticsStub = sinon
-    const logger = getRunnerLogger(true);
+    .stub(overlayDiagnostics, "addOverlayDisablementDiagnostics")
-    const addDiagnosticsStub = sinon
+    .resolves();
-      .stub(overlayDiagnostics, "addOverlayDisablementDiagnostics")
-      .resolves();
 
-    await configUtils.applyIncrementalAnalysisSettings(
+  await configUtils.applyIncrementalAnalysisSettings(
-      config,
+    config,
-      false,
+    false,
-      codeql,
+    codeql,
-      logger,
+    logger,
-    );
+  );
 
-    t.is(config.overlayDatabaseMode, OverlayDatabaseMode.None);
+  t.is(config.overlayDatabaseMode, OverlayDatabaseMode.None);
-    t.is(config.useOverlayDatabaseCaching, false);
+  t.is(config.useOverlayDatabaseCaching, false);
-    t.deepEqual(config.extraQueryExclusions, []);
+  t.deepEqual(config.extraQueryExclusions, []);
-    t.true(addDiagnosticsStub.calledOnce);
+  t.true(addDiagnosticsStub.calledOnce);
-    t.is(
+  t.is(
-      addDiagnosticsStub.firstCall.args[2],
+    addDiagnosticsStub.firstCall.args[2],
-      OverlayDisabledReason.DiffInformedAnalysisNotEnabled,
+    OverlayDisabledReason.DiffInformedAnalysisNotEnabled,
-    );
+  );
-  },
+});
-);
-
-test.serial(
-  "applyIncrementalAnalysisSettings: keeps overlay mode when set explicitly and diff ranges are unavailable",
-  async (t) => {
-    const config = createTestConfig({
-      overlayDatabaseMode: OverlayDatabaseMode.Overlay,
-    });
-    config.useOverlayDatabaseCaching = false;
-    config.overlayModeSetExplicitly = true;
-    const codeql = createStubCodeQL({});
-    const logger = getRunnerLogger(true);
-    const addDiagnosticsStub = sinon
-      .stub(overlayDiagnostics, "addOverlayDisablementDiagnostics")
-      .resolves();
-
-    await configUtils.applyIncrementalAnalysisSettings(
-      config,
-      false,
-      codeql,
-      logger,
-    );
-
-    t.is(config.overlayDatabaseMode, OverlayDatabaseMode.Overlay);
-    t.is(config.useOverlayDatabaseCaching, false);
-    t.deepEqual(config.extraQueryExclusions, []);
-    t.true(addDiagnosticsStub.notCalled);
-  },
-);
 
 test("applyIncrementalAnalysisSettings: adds exclusions for diff-informed-only runs", async (t) => {
   const config = createTestConfig({});

src/config-utils.ts

@@ -243,11 +243,6 @@ export interface Config {
    */
   useOverlayDatabaseCaching: boolean;
 
-  /**
-   * Whether the overlay database mode was set explicitly.
-   */
-  overlayModeSetExplicitly: boolean;
-
   /**
    * A partial mapping from repository properties that affect us to their values.
    */
@@ -578,7 +573,6 @@ export async function initActionState(
     extraQueryExclusions: [],
     overlayDatabaseMode: OverlayDatabaseMode.None,
     useOverlayDatabaseCaching: false,
-    overlayModeSetExplicitly: false,
     repositoryProperties,
     enableFileCoverageInformation,
   };
@@ -778,7 +772,6 @@ async function checkRunnerResources(
 interface EnabledOverlayConfig {
   overlayDatabaseMode: Exclude<OverlayDatabaseMode, OverlayDatabaseMode.None>;
   useOverlayDatabaseCaching: boolean;
-  overlayModeSetExplicitly: boolean;
 }
 
 /**
@@ -833,7 +826,6 @@ export async function checkOverlayEnablement(
     return validateOverlayDatabaseMode(
       modeEnv,
       false,
-      true,
       codeql,
       languages,
       sourceRoot,
@@ -925,7 +917,6 @@ export async function checkOverlayEnablement(
   return validateOverlayDatabaseMode(
     overlayDatabaseMode,
     true,
-    false,
     codeql,
     languages,
     sourceRoot,
@@ -944,7 +935,6 @@ export async function checkOverlayEnablement(
 async function validateOverlayDatabaseMode(
   overlayDatabaseMode: Exclude<OverlayDatabaseMode, OverlayDatabaseMode.None>,
   useOverlayDatabaseCaching: boolean,
-  overlayModeSetExplicitly: boolean,
   codeql: CodeQL,
   languages: Language[],
   sourceRoot: string,
@@ -1016,7 +1006,6 @@ async function validateOverlayDatabaseMode(
   return new Success({
     overlayDatabaseMode,
     useOverlayDatabaseCaching,
-    overlayModeSetExplicitly,
   });
 }
 
@@ -1091,14 +1080,14 @@ function hasQueryCustomisation(userConfig: UserConfig): boolean {
 /**
  * Finalize the incremental-analysis configuration for this run.
  *
- * Overlay analysis has only been validated in combination with diff-informed analysis, so if
+ * Overlay analysis has only been validated in combination with diff-informed
- * `Overlay` mode was selected for a pull request but the diff ranges could not be computed, fall
+ * analysis, so if `Overlay` mode was selected for a pull request but the diff
- * back to a full non-overlay analysis. If the overlay mode was set explicitly, this fallback does
+ * ranges could not be computed, fall back to a full non-overlay analysis.
- * not apply.
  *
- * Query exclusions for incremental-only queries are then applied whenever the diff ranges are
+ * Query exclusions for incremental-only queries are then applied whenever the
- * available — which, after the fallback above, is exactly the set of runs where any kind of
+ * diff ranges are available — which, after the fallback above, is exactly the
- * incremental analysis (overlay or diff-informed) is in effect.
+ * set of runs where any kind of incremental analysis (overlay or
+ * diff-informed) is in effect.
  */
 export async function applyIncrementalAnalysisSettings(
   config: Config,
@@ -1108,8 +1097,7 @@ export async function applyIncrementalAnalysisSettings(
 ): Promise<void> {
   if (
     config.overlayDatabaseMode === OverlayDatabaseMode.Overlay &&
-    !hasDiffRanges &&
+    !hasDiffRanges
-    !config.overlayModeSetExplicitly
   ) {
     logger.info(
       `Reverting overlay database mode to ${OverlayDatabaseMode.None} ` +
@@ -1263,18 +1251,14 @@ export async function initConfig(
     logger,
   );
   if (overlayDatabaseModeResult.isSuccess()) {
-    const {
+    const { overlayDatabaseMode, useOverlayDatabaseCaching } =
-      overlayDatabaseMode,
+      overlayDatabaseModeResult.value;
-      useOverlayDatabaseCaching,
-      overlayModeSetExplicitly,
-    } = overlayDatabaseModeResult.value;
     logger.info(
       `Using overlay database mode: ${overlayDatabaseMode} ` +
         `${useOverlayDatabaseCaching ? "with" : "without"} caching.`,
     );
     config.overlayDatabaseMode = overlayDatabaseMode;
     config.useOverlayDatabaseCaching = useOverlayDatabaseCaching;
-    config.overlayModeSetExplicitly = overlayModeSetExplicitly;
   } else {
     const overlayDisabledReason = overlayDatabaseModeResult.value;
     logger.info(

src/feature-flags.ts

@@ -82,6 +82,11 @@ export enum Feature {
   DisableJavaBuildlessEnabled = "disable_java_buildless_enabled",
   DisableKotlinAnalysisEnabled = "disable_kotlin_analysis_enabled",
   ExportDiagnosticsEnabled = "export_diagnostics_enabled",
+  /**
+   * Emergency override that forces the CodeQL CLI to use the JGit-based Git backend instead of its
+   * default backend selection.
+   */
+  ForceJGit = "force_jgit",
   ForceNightly = "force_nightly",
   IgnoreGeneratedFiles = "ignore_generated_files",
   JavaNetworkDebugging = "java_network_debugging",
@@ -224,6 +229,11 @@ export const featureConfig = {
     legacyApi: true,
     minimumVersion: undefined,
   },
+  [Feature.ForceJGit]: {
+    defaultValue: false,
+    envVar: "CODEQL_ACTION_FORCE_JGIT",
+    minimumVersion: undefined,
+  },
   [Feature.ForceNightly]: {
     defaultValue: false,
     envVar: "CODEQL_ACTION_FORCE_NIGHTLY",

src/init-action.ts

@@ -614,6 +614,11 @@ async function run(startedAt: Date) {
       core.exportVariable("CODEQL_EXTRACTOR_JAVA_AGENT_DISABLE_KOTLIN", "true");
     }
 
+    // Emergency override to force the CodeQL CLI back to the JGit-based Git backend.
+    if (await features.getValue(Feature.ForceJGit)) {
+      core.exportVariable("CODEQL_GIT_BACKEND", "jgit");
+    }
+
     const kotlinLimitVar =
       "CODEQL_EXTRACTOR_KOTLIN_OVERRIDE_MAXIMUM_VERSION_LIMIT";
     if (

src/testing-utils.ts

@@ -585,7 +585,6 @@ export function createTestConfig(overrides: Partial<Config>): Config {
       extraQueryExclusions: [],
       overlayDatabaseMode: OverlayDatabaseMode.None,
       useOverlayDatabaseCaching: false,
-      overlayModeSetExplicitly: false,
       repositoryProperties: {},
       enableFileCoverageInformation: true,
     } satisfies Config,