workflow/labels: fix scheduled runs (#417250)

.github/workflows/labels.yml

@@ -69,13 +69,14 @@ jobs:
               // Normally a scheduled run, but could be workflow_dispatch, see above. Go back as far
               // as the last successful run of this workflow to make sure we are not leaving anyone
               // behind on GHA failures.
+              // Defaults to go back 1 hour on the first run.
               return (await github.rest.actions.listWorkflowRuns({
                 ...context.repo,
                 workflow_id: 'labels.yml',
                 event: 'schedule',
                 status: 'success',
                 exclude_pull_requests: true
-              })).data.workflow_runs[0]?.created_at
+              })).data.workflow_runs[0]?.created_at ?? new Date().getTime() - 1 * 60 * 60 * 1000
             })())
             core.info('cutoff timestamp: ' + cutoff.toISOString())
 
@@ -98,7 +99,8 @@ jobs:
                 direction: 'desc',
                 ...prEventCondition
               },
-              async (response, done) => await Promise.all(response.data.map(async (pull_request) => {
+              async (response, done) => (await Promise.allSettled(response.data.map(async (pull_request) => {
+                try {
                   const log = (k,v) => core.info(`PR #${pull_request.number} - ${k}: ${v}`)
 
                   log('Last updated at', pull_request.updated_at)
@@ -136,7 +138,7 @@ jobs:
                       repositoryOwner: context.repo.owner,
                       token: core.getInput('github-token')
                     },
-                  path: path.resolve('comparison'),
+                    path: path.resolve(pull_request.number.toString()),
                     expectedHash: artifact.digest
                   })
 
@@ -160,11 +162,11 @@ jobs:
                   )
 
                   const maintainers = new Set(Object.keys(
-                  JSON.parse(await readFile('comparison/maintainers.json', 'utf-8'))
+                    JSON.parse(await readFile(`${pull_request.number}/maintainers.json`, 'utf-8'))
                   ))
 
                   // And the labels that should be there
-                const after = JSON.parse(await readFile('comparison/changed-paths.json', 'utf-8')).labels
+                  const after = JSON.parse(await readFile(`${pull_request.number}/changed-paths.json`, 'utf-8')).labels
                   if (approvals.size > 0) after.push(`12.approvals: ${approvals.size > 2 ? '3+' : approvals.size}`)
                   if (Array.from(maintainers).some(m => approvals.has(m))) after.push('12.approved-by: package-maintainer')
 
@@ -187,7 +189,12 @@ jobs:
                       labels: added
                     })
                   }
-              }))
+                } catch (cause) {
+                  throw new Error(`Labeling PR #${pull_request.number} failed.`, { cause })
+                }
+              })))
+              .filter(({ status }) => status == 'rejected')
+              .map(({ reason }) => core.setFailed(`${reason.message}\n${reason.cause.stack}`))
             )
 
       - uses: actions/labeler@8558fd74291d67161a8a78ce36a881fa63b766a9 # v5.0.0