fix(worker): clean up orphaned zoekt .tmp shard files after every index attempt

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- Cleaned up orphaned zoekt `.tmp` shard files on every indexing attempt, not just on failure, so leftovers from previously interrupted runs are removed. [#1214](https://github.com/sourcebot-dev/sourcebot/pull/1214)
+
 ## [4.17.2] - 2026-05-16
 
 ### Added

packages/backend/src/repoIndexManager.test.ts

@@ -56,6 +56,7 @@ vi.mock('./git.js', () => ({
 
 vi.mock('./zoekt.js', () => ({
     indexGitRepository: vi.fn().mockResolvedValue({ stdout: '', stderr: '' }),
+    cleanupTempShards: vi.fn().mockResolvedValue(undefined),
 }));
 
 vi.mock('./posthog.js', () => ({

packages/backend/src/repoIndexManager.ts

@@ -516,11 +516,15 @@ export class RepoIndexManager {
             const indexDuration_s = durationMs / 1000;
             logger.debug(`Indexed ${repo.name} (id: ${repo.id}) in ${indexDuration_s}s`);
         } catch (error) {
-            // Clean up any temporary shard files left behind by the failed indexing operation.
-            // Zoekt creates .tmp files during indexing which can accumulate if indexing fails repeatedly.
-            logger.warn(`Indexing failed for ${repo.name} (id: ${repo.id}), cleaning up temp shard files...`);
-            await cleanupTempShards(repo);
+            logger.warn(`Indexing failed for ${repo.name} (id: ${repo.id}).`);
             throw error;
+        } finally {
+            // Zoekt writes shards to a .tmp file first, then atomically renames them to their final
+            // name. If the process is killed or interrupted during the rename loop, some .tmp files
+            // may be left behind that zoekt won't clean up on the next run (it only tracks temp
+            // files from the current build). Running cleanup here ensures orphans from previous
+            // interrupted runs are removed.
+            await cleanupTempShards(repo);
         }
 
         return revisions;