github
diff --git a/‎lib/init-action.js‎
Lines changed: 6 additions & 0 deletions b/‎lib/init-action.js‎
Lines changed: 6 additions & 0 deletions
diff --git a/‎src/init-action.ts‎
Lines changed: 12 additions & 0 deletions b/‎src/init-action.ts‎
Lines changed: 12 additions & 0 deletions
@@ -201,6 +201,10 @@ async function run() {
     ? await loadPropertiesFromApi(gitHubVersion, logger, repositoryNwo)
     : {};
 
+  // Store the previous value of `JOB_RUN_UUID`, if any.
+  const previousJobRunUuid = process.env[EnvVar.JOB_RUN_UUID];
+
+  // Create a unique identifier for this run.
   const jobRunUuid = uuidV4();
   logger.info(`Job run UUID is ${jobRunUuid}.`);
   core.exportVariable(EnvVar.JOB_RUN_UUID, jobRunUuid);
@@ -229,6 +233,14 @@ async function run() {
     if (statusReportBase !== undefined) {
       await sendStatusReport(statusReportBase);
     }
+
+    // Throw a `ConfigurationError` if `previousJobRunUuid` is defined and not empty.
+    if (previousJobRunUuid !== undefined && previousJobRunUuid.trim() !== "") {
+      throw new ConfigurationError(
+        `${EnvVar.JOB_RUN_UUID} was already set to '${previousJobRunUuid}'. The 'init' action should only be run once, and not in the same workflow as 'setup-codeql'.`,
+      );
+    }
+
     const codeQLDefaultVersionInfo = await features.getDefaultCliVersion(
       gitHubVersion.type,
     );