[ci] Fix bazel check for changes (#28)

* Add tmp echo debug statements

* Simulate changes in test

* try

* quick test

* patch for now

* undo

ci/check_bazel.sh

@@ -11,11 +11,15 @@ set -euo pipefail
 # Trap to handle unexpected errors and log them
 trap 'echo "An unexpected error occurred during Bazel check."; echo "check_result=1" >> "$GITHUB_OUTPUT"; exit 1' ERR
 
-# Ensure we fetch the base branch (main) to make it available
-git fetch origin "$GITHUB_BASE_REF":"$GITHUB_BASE_REF"
+# Check if GITHUB_BASE_REF is set (i.e., you're in a pull request)
+if [ -n "$GITHUB_BASE_REF" ]; then
+  git fetch origin "$GITHUB_BASE_REF":"$GITHUB_BASE_REF"
+  base_sha=$(git rev-parse "$GITHUB_BASE_REF")
+else
+  echo "Not in a pull request, skipping base ref fetch."
+  base_sha=$(git rev-parse HEAD)
+fi
 
-# Get the latest commit SHA for the base branch (target branch of the PR)
-base_sha=$(git rev-parse "$GITHUB_BASE_REF")
 # Get the latest commit SHA for the PR branch (the head ref in the forked repository)
 final_revision=$GITHUB_SHA