log waring for unavaiable labels

lib/modules/platform/gitea/index.spec.ts

@@ -1875,6 +1875,48 @@ describe('modules/platform/gitea/index', () => {
         }),
       ).toResolve();
     });
+
+    it('should log a warning if labels could not be looked up', async () => {
+      const updatedMockPR = partial<PR>({
+        ...mockPRs[0],
+        number: 1,
+        title: 'New Title',
+        body: 'New Body',
+        state: 'open',
+        labels: [
+          {
+            id: 1,
+            name: 'some-label',
+          },
+        ],
+      });
+      const scope = httpMock
+        .scope('https://gitea.com/api/v1')
+        .get('/repos/some/repo/pulls')
+        .query({ state: 'all', sort: 'recentupdate' })
+        .reply(200, mockPRs)
+        .get('/repos/some/repo/labels')
+        .reply(200, mockRepoLabels)
+        .get('/orgs/some/labels')
+        .reply(200, mockOrgLabels)
+        .patch('/repos/some/repo/pulls/1')
+        .reply(200, updatedMockPR);
+
+      await initFakePlatform(scope);
+      await initFakeRepo(scope);
+      await expect(
+        gitea.updatePr({
+          number: 1,
+          prTitle: 'New Title',
+          prBody: 'New Body',
+          state: 'open',
+          labels: ['some-label', 'unavailable-label'],
+        }),
+      ).toResolve();
+      expect(logger.warn).toHaveBeenCalledWith(
+        'Some labels could not be looked up. Renovate may halt label updates assuming changes by others.',
+      );
+    });
   });
 
   describe('mergePr', () => {

lib/modules/platform/gitea/index.ts

@@ -612,6 +612,11 @@ const platform: Platform = {
       prUpdateParams.labels = (await map(labels, lookupLabelByName)).filter(
         is.number,
       );
+      if (labels.length !== prUpdateParams.labels.length) {
+        logger.warn(
+          'Some labels could not be looked up. Renovate may halt label updates assuming changes by others.',
+        );
+      }
     }
 
     const gpr = await helper.updatePR(