brew CI: check RTOOLS_BRANCH for ci_matching_branch

Signed-off-by: Steve Peters <scpeters@intrinsic.ai>

Author: scpeters

jenkins-scripts/lib/project-default-devel-homebrew-amd64.bash

@@ -59,10 +59,21 @@ echo '# END SECTION'
 if [[ -n "${ghprbSourceBranch}" ]] && \
    python3 ${SCRIPT_DIR}/tools/detect_ci_matching_branch.py "${ghprbSourceBranch}"
 then
-  echo "# BEGIN SECTION: trying to checkout branch ${ghprbSourceBranch} from osrf/simulation"
+  export CI_MATCHING_BRANCH=${ghprbSourceBranch}
+fi
+
+if [[ -n "${RTOOLS_BRANCH}" ]] && \
+   python3 ${SCRIPT_DIR}/tools/detect_ci_matching_branch.py "${RTOOLS_BRANCH}"
+then
+  export CI_MATCHING_BRANCH=${RTOOLS_BRANCH}
+fi
+
+if [[ -n "${CI_MATCHING_BRANCH}" ]]
+then
+  echo "# BEGIN SECTION: trying to checkout branch ${CI_MATCHING_BRANCH} from osrf/simulation"
   pushd $(brew --repo osrf/simulation)
-  git fetch origin ${ghprbSourceBranch} || true
-  git checkout ${ghprbSourceBranch} || true
+  git fetch origin ${CI_MATCHING_BRANCH} || true
+  git checkout ${CI_MATCHING_BRANCH} || true
   popd
   echo '# END SECTION'
 fi