diff --git a/ci/build_setup.sh b/ci/build_setup.sh
index a44d0c14d4c37..cedbda30a9e86 100755
--- a/ci/build_setup.sh
+++ b/ci/build_setup.sh
@@ -64,8 +64,9 @@ then
 fi
 
 # Environment setup.
-export TEST_TMPDIR=${BUILD_DIR}/tmp
-export PATH=/opt/llvm/bin:${PATH}
+export TEST_TMPDIR="${TEST_TMPDIR:-$BUILD_DIR/tmp}"
+export LLVM_ROOT="${LLVM_ROOT:-/opt/llvm}"
+export PATH=${LLVM_ROOT}/bin:${PATH}
 export CLANG_FORMAT="${CLANG_FORMAT:-clang-format}"
 
 if [[ -f "/etc/redhat-release" ]]; then
@@ -81,7 +82,6 @@ function cleanup() {
 cleanup
 trap cleanup EXIT
 
-export LLVM_ROOT="${LLVM_ROOT:-/opt/llvm}"
 "$(dirname "$0")"/../bazel/setup_clang.sh "${LLVM_ROOT}"
 
 [[ "${BUILD_REASON}" != "PullRequest" ]] && BAZEL_EXTRA_TEST_OPTIONS+=("--nocache_test_results")