ci: cleanup CircleCI fetch phases

.circleci/config.yml

@@ -28,7 +28,7 @@ jobs:
     steps:
       - checkout
       # need to init some stuff first or git will complain when sticking in base cache
-      - run: git submodule init base && git submodule update base && pushd base && git submodule init && git submodule update && popd
+      - run: git submodule update --init base && git -C base submodule update --depth 1 --init --jobs 3 --recursive
       # we can't use command output directly for cache check so we write it to git-rev-base
       - run: pushd base && git_rev_base=$(git describe HEAD) && popd && echo $git_rev_base && echo $git_rev_base >git-rev-base
       - restore_cache:
@@ -80,14 +80,9 @@ jobs:
     parallelism: 1
     steps:
       - checkout
-      # need to init some stuff first or git will complain when sticking in base cache
-      - run: git submodule init base && git submodule update base && pushd base && git submodule init && git submodule update && popd
-      # we can't use command output directly for cache check so we write it to git-rev-base
-      - run: pushd base && git_rev_base=$(git describe HEAD) && popd && echo $git_rev_base && echo $git_rev_base >git-rev-base
-
       - run:
-          name: init-submodules
-          command: git submodule init && git submodule sync && git submodule update
+          name: fetch
+          command: .ci/fetch.sh
 
       # docs, coverage, and test timing (can we use two outputs at once?); master branch only
       - run: