ci: improve stability of windows bazel CI job (#45431)

Improves stability of the Windows Bazel CI job by
installing Bazelisk globally.

Also makes the environment helpers more convenient by
evaluating the variable assignments directly, simplifying
some Bash logic.

PR Close #45431

.circleci/config.yml

@@ -715,15 +715,21 @@ jobs:
             - *cache_key_win
             - *cache_key_win_fallback
 
+      # Install project dependencies, and install Bazelisk globally. This is necessary as
+      # Windows might error when `bazel` is invoked from the project node modules. The Bazel
+      # invocation might modify the symlinked project `node_modules` again, causing failures.
       - yarn_install
+      - run: yarn global add @bazel/bazelisk@${BAZELISK_VERSION}
 
       - run:
           name: Build all windows CI targets
-          command: yarn bazel build //packages/compiler-cli/...
+          command: |
+            $(yarn global bin)/bazelisk build //packages/compiler-cli/...
           no_output_timeout: 15m
       - run:
           name: Test all windows CI targets
-          command: yarn bazel test --test_tag_filters="-browser:chromium-local" //packages/compiler-cli/...
+          command: |
+            $(yarn global bin)/bazelisk test --test_tag_filters="-browser:chromium-local" //packages/compiler-cli/...
           no_output_timeout: 15m
 
       - save_cache:

.circleci/env-helpers.inc.sh

@@ -31,7 +31,10 @@ function setSecretVar() {
   local -r originalShellOptions=$(set +o);
   set +x -eu -o pipefail;
 
-  echo "export $1=\"${2:-}\";" >> $BASH_ENV;
+  local assignmentStatement="export $1=\"${2:-}\";"
+
+  echo "${assignmentStatement}" >> $BASH_ENV;
+  eval "${assignmentStatement}"
 
   # Restore original shell options.
   eval "$originalShellOptions";

.circleci/env.sh

@@ -91,14 +91,6 @@ echo "export CI_REPO_NAME=\"${CI_REPO_NAME}\";" >> $bazelVarEnv
 echo "export CI_REPO_OWNER=\"${CI_REPO_OWNER}\";" >> $bazelVarEnv
 echo "export CI_SECRET_PAYLOAD_FIREBASE_TOKEN=\"${CI_SECRET_PAYLOAD_FIREBASE_TOKEN}\";" >> $bazelVarEnv
 
-####################################################################################################
-####################################################################################################
-##                  Source `$BASH_ENV` to make the variables available immediately.               ##
-##                  ***NOTE: This must remain the last variable definition in this script***      ##
-####################################################################################################
-####################################################################################################
-source $BASH_ENV;
-
 ####################################################################################################
 # Platform-specific environment setup (which can leverage the base variables from here)
 ####################################################################################################

.circleci/env.windows.sh

@@ -9,3 +9,9 @@ openssl aes-256-cbc -d -in "${PROJECT_ROOT}/.circleci/gcp_token" \
 # Set bazel configuration for CircleCI runs.
 ####################################################################################################
 cp "${PROJECT_ROOT}/.circleci/bazel.windows.rc" "${USERPROFILE}/.bazelrc";
+
+
+# Expose the Bazelisk version. We need to run Bazelisk globally since Windows has problems launching
+# Bazel from a node modules directoy that might be modified by the Bazel Yarn install then.
+setPublicVar BAZELISK_VERSION \
+    "$(cd ${PROJECT_ROOT}; node -p 'require("./package.json").devDependencies["@bazel/bazelisk"]')"