Write artifacts to `build` instead of `build2`

Now that all the CI jobs have been migrated to the new build script,
we can start renaming the `build2` directory to `build`.

Since there are lots of scripts that reference `build2`, including
downstream scripts that live outside this repo, I'm going to keep
the `build2` directory around as a copy of `build`.

Then once all the references are updated, I will delete the copy.

.circleci/config.yml

@@ -158,8 +158,10 @@ jobs:
       - run: yarn build-combined
       - persist_to_workspace:
           root: .
+          # TODO: Migrate scripts to use `build` directory instead of `build2`
           paths:
             - build2
+            - build
 
   get_base_build:
     docker: *docker
@@ -192,8 +194,12 @@ jobs:
       - run: echo "<< pipeline.git.revision	>>" >> build2/COMMIT_SHA
         # Compress build directory into a single tarball for easy download
       - run: tar -zcvf ./build2.tgz ./build2
+        # TODO: Migrate scripts to use `build` directory instead of `build2`
+      - run: tar -zcvf ./build.tgz ./build
       - store_artifacts:
           path: ./build2.tgz
+      - store_artifacts:
+          path: ./build.tgz
 
   sizebot:
     docker: *docker

scripts/rollup/build-all-release-channels.js

@@ -57,9 +57,10 @@ if (process.env.CIRCLE_NODE_TOTAL) {
     processExperimental('./build');
   }
 
-  // TODO: Currently storing artifacts as `./build2` so that it doesn't conflict
-  // with old build job. Remove once we migrate rest of build/test pipeline.
-  fs.renameSync('./build', './build2');
+  // TODO: Currently storing a copy of the artifacts as `./build2`, because
+  // some scripts reference that directory. Remove once we migrate everything to
+  // reference `./build` instead.
+  fse.copySync('./build', './build2');
 } else {
   // Running locally, no concurrency. Move each channel's build artifacts into
   // a temporary directory so that they don't conflict.
@@ -85,9 +86,11 @@ if (process.env.CIRCLE_NODE_TOTAL) {
   mergeDirsSync(experimentalDir + '/', stableDir + '/');
 
   // Now restore the combined directory back to its original name
-  // TODO: Currently storing artifacts as `./build2` so that it doesn't conflict
-  // with old build job. Remove once we migrate rest of build/test pipeline.
-  crossDeviceRenameSync(stableDir, './build2');
+  crossDeviceRenameSync(stableDir, './build');
+  // TODO: Currently storing a copy of the artifacts as `./build2`, because
+  // some scripts reference that directory. Remove once we migrate everything to
+  // reference `./build` instead.
+  fse.copySync('./build', './build2');
 }
 
 function buildForChannel(channel, nodeTotal, nodeIndex) {