From b611fd02a40f2b1a1ede3ebe9b75e2fcfad79fed Mon Sep 17 00:00:00 2001
From: Beth Griggs <bethanyngriggs@gmail.com>
Date: Tue, 16 Apr 2024 18:10:05 +0100
Subject: [PATCH] fix: handle lost+found directory in plugin scanner

Signed-off-by: Beth Griggs <bethanyngriggs@gmail.com>
---
 .changeset/smart-avocados-invent.md            |  5 +++++
 .../src/scanner/plugin-scanner.test.ts         | 18 ++++++++++++++++++
 .../src/scanner/plugin-scanner.ts              |  5 +++++
 3 files changed, 28 insertions(+)
 create mode 100644 .changeset/smart-avocados-invent.md

diff --git a/.changeset/smart-avocados-invent.md b/.changeset/smart-avocados-invent.md
new file mode 100644
index 0000000000..c71b6fef37
--- /dev/null
+++ b/.changeset/smart-avocados-invent.md
@@ -0,0 +1,5 @@
+---
+'@backstage/backend-dynamic-feature-service': patch
+---
+
+Updates the `scanRoot` method in the `PluginScanner` class to specifically ignore the `lost+found` directory, which is a system-generated directory used for file recovery on Unix-like systems. Skipping this directory avoids unnecessary errors.
diff --git a/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.test.ts b/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.test.ts
index 1abd7c234c..3086f2c16e 100644
--- a/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.test.ts
+++ b/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.test.ts
@@ -636,6 +636,24 @@ Please add '${mockDir.resolve(
           ],
         },
       },
+      {
+        name: 'lost+found directory should be ignored',
+        fileSystem: {
+          backstageRoot: {
+            'dist-dynamic': {
+              'lost+found': {},
+            },
+          },
+        },
+        expectedPluginPackages: [],
+        expectedLogs: {
+          debugs: [
+            {
+              message: `skipping 'lost+found' system directory`,
+            },
+          ],
+        },
+      },
     ])('$name', async (tc: TestCase): Promise<void> => {
       const logger = new MockedLogger();
       const backstageRoot = mockDir.resolve('backstageRoot');
diff --git a/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.ts b/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.ts
index af1144f019..9229f5d78a 100644
--- a/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.ts
+++ b/packages/backend-dynamic-feature-service/src/scanner/plugin-scanner.ts
@@ -136,6 +136,11 @@ export class PluginScanner {
       withFileTypes: true,
     })) {
       const pluginDir = dirEnt;
+
+      if (pluginDir.name === 'lost+found') {
+        this.logger.debug(`skipping '${pluginDir.name}' system directory`);
+        continue;
+      }
       const pluginHome = path.normalize(
         path.resolve(dynamicPluginsLocation, pluginDir.name),
       );