Restore the TODO comment

Author: huydhn

.ci/scripts/setup-macos.sh

@@ -28,6 +28,16 @@ install_buck() {
   fi
 
   pushd .ci/docker
+  # TODO(huydo): This is a one-off copy of buck2 2024-05-15 to unblock Jon and
+  # re-enable ShipIt. It’s not ideal that upgrading buck2 will require a manual
+  # update the cached binary on S3 bucket too. Let me figure out if there is a
+  # way to correctly implement the previous setup of installing a new version of
+  # buck2 only when it’s needed. AFAIK, the complicated part was that buck2
+  # --version doesn't say anything w.r.t its release version, i.e. 2024-05-15.
+  # See D53878006 for more details.
+  #
+  # If you need to upgrade buck2 version on S3, please reach out to Dev Infra
+  # team for help.
   BUCK2_VERSION=$(cat ci_commit_pins/buck2.txt)
   BUCK2=buck2-aarch64-apple-darwin-${BUCK2_VERSION}.zst
   curl -s "https://ossci-macos.s3.amazonaws.com/${BUCK2}" -o "${BUCK2}"