Move GitHub status check inside retry loop

The download script will poll the CircleCI endpoint until the build job
is complete; it should also poll the GitHub status endpoint if the
build job hasn't been spawned yet.

.circleci/config.yml

@@ -187,7 +187,7 @@ jobs:
           # branch. Once they do, replace with `merge-base HEAD origin/master`
           command: |
               git fetch origin master
-              echo "$(merge-base HEAD origin/master)"
+              echo "$(git merge-base HEAD origin/master)"
               cd ./scripts/release && yarn && cd ../../
               scripts/release/download-experimental-build.js --commit=6b8d4ca
               mv ./build2 ./base-build

scripts/release/get-build-id-for-commit.js

@@ -35,13 +35,15 @@ async function getBuildIdForCommit(sha) {
         if (status.state === 'failure') {
           throw new Error(`Build job for commit failed: ${sha}`);
         }
-        if (Date.now() < retryLimit) {
-          await wait(POLLING_INTERVAL);
-          continue retry;
-        }
-        throw new Error('Exceeded retry limit. Build job is still pending.');
       }
     }
+    if (state === 'pending') {
+      if (Date.now() < retryLimit) {
+        await wait(POLLING_INTERVAL);
+        continue retry;
+      }
+      throw new Error('Exceeded retry limit. Build job is still pending.');
+    }
     throw new Error('Could not find build for commit: ' + sha);
   }
 }