diff --git a/release/run_release_test.sh b/release/run_release_test.sh
index 88e9babd0a0f..8dac0ae999f8 100755
--- a/release/run_release_test.sh
+++ b/release/run_release_test.sh
@@ -3,25 +3,21 @@
 
 set -e
 
-if [ -n "$DEBUG" ]; then
-  set -x
-fi
-
 cd "${0%/*}" || exit 1
 
 reason() {
   # Keep in sync with e2e.py ExitCode enum
-  if [ "$1" -eq 0 ]; then
+  if [[ "$1" -eq 0 ]]; then
     REASON="success"
-  elif [ "$1" -ge 1 ] && [ "$1" -lt 10 ]; then
+  elif [[ "$1" -ge 1 && "$1" -lt 10 ]]; then
     REASON="runtime error"
-  elif [ "$1" -ge 10 ] && [ "$1" -lt 20 ]; then
+  elif [[ "$1" -ge 10 && "$1" -lt 20 ]]; then
     REASON="infra error"
-  elif [ "$1" -ge 30 ] && [ "$1" -lt 40 ]; then
+  elif [[ "$1" -ge 30 && "$1" -lt 40 ]]; then
     REASON="infra timeout"
-  elif [ "$1" -eq 42 ]; then
+  elif [[ "$1" -eq 42 ]]; then
     REASON="command timeout"
-  elif [ "$1" -ge 40 ] && [ "$1" -lt 50 ]; then
+  elif [[ "$1" -ge 40 && "$1" -lt 50 ]]; then
     REASON="command error"
   fi
   echo "${REASON}"
@@ -35,7 +31,7 @@ BUILDKITE_TIME_LIMIT_FOR_RETRY=10800 # 3 hours
 
 export RAY_TEST_REPO RAY_TEST_BRANCH RELEASE_RESULTS_DIR BUILDKITE_MAX_RETRIES BUILDKITE_RETRY_CODE BUILDKITE_TIME_LIMIT_FOR_RETRY
 
-if [ -n "${RAY_COMMIT_OF_WHEEL-}" ]; then
+if [[ -n "${RAY_COMMIT_OF_WHEEL-}" ]]; then
   git config --global --add safe.directory /workdir
   HEAD_COMMIT=$(git rev-parse HEAD)
   echo "The test repo has head commit of ${HEAD_COMMIT}"
@@ -48,7 +44,7 @@ if [ -n "${RAY_COMMIT_OF_WHEEL-}" ]; then
   fi
 fi
 
-if [ -z "${NO_INSTALL}" ]; then
+if [[ -z "${NO_INSTALL}" ]]; then
   # Strip the hashes from the constraint file
   # TODO(aslonnie): use bazel run..
   grep '==' ./requirements_buildkite.txt > /tmp/requirements_buildkite_nohash.txt
@@ -60,20 +56,20 @@ fi
 RETRY_NUM=0
 MAX_RETRIES=${MAX_RETRIES-1}
 
-if [ "${BUILDKITE_RETRY_COUNT-0}" -ge 1 ]; then
+if [[ "${BUILDKITE_RETRY_COUNT-0}" -ge 1 ]]; then
   echo "This is a manually triggered retry from the Buildkite web UI, so we set the number of infra retries to 1."
   MAX_RETRIES=1
 fi
 
 ALL_EXIT_CODES=()
-while [ "$RETRY_NUM" -lt "$MAX_RETRIES" ]; do
+while [[ "$RETRY_NUM" -lt "$MAX_RETRIES" ]]; do
   RETRY_NUM=$((RETRY_NUM + 1))
 
-  if [ "$RETRY_NUM" -gt 1 ]; then
+  if [[ "$RETRY_NUM" -gt 1 ]]; then
     # Sleep for random time between 30 and 90 minutes
     SLEEP_TIME=$((1800 + RANDOM % 5400))
 
-    if [ -n "${OVERRIDE_SLEEP_TIME}" ]; then
+    if [[ -n "${OVERRIDE_SLEEP_TIME}" ]]; then
       SLEEP_TIME=${OVERRIDE_SLEEP_TIME}
     fi
 
@@ -83,7 +79,7 @@ while [ "$RETRY_NUM" -lt "$MAX_RETRIES" ]; do
     sleep "${SLEEP_TIME}"
   fi
 
-  if [ -z "${NO_ARTIFACTS}" ]; then
+  if [[ -z "${NO_ARTIFACTS}" ]]; then
     rm -rf "${RELEASE_RESULTS_DIR:?}"/* || true
   fi
 
@@ -131,7 +127,7 @@ while [ "$RETRY_NUM" -lt "$MAX_RETRIES" ]; do
 
 done
 
-if [ -z "${NO_ARTIFACTS}" ]; then
+if [[ -z "${NO_ARTIFACTS}" ]]; then
   rm -rf /tmp/ray_release_test_artifacts/* || true
   cp -rf "${RELEASE_RESULTS_DIR}"/* /tmp/ray_release_test_artifacts/ || true
 fi
@@ -152,9 +148,9 @@ echo "----------------------------------------"
 REASON=$(reason "${EXIT_CODE}")
 echo "Final release test exit code is ${EXIT_CODE} (${REASON}). Took ${RUNTIME}s"
 
-if [ "$EXIT_CODE" -eq 0 ]; then
+if [[ "$EXIT_CODE" -eq 0 ]]; then
   echo "RELEASE MANAGER: This test seems to have passed."
-elif [ "$EXIT_CODE" -ge 30 ] && [ "$EXIT_CODE" -lt 40 ]; then
+elif [[ "$EXIT_CODE" -ge 30 && "$EXIT_CODE" -lt 40 ]]; then
   echo "RELEASE MANAGER: This is likely an infra error that can be solved by RESTARTING this test."
 else
   echo "RELEASE MANAGER: This could be an error in the test. Please REVIEW THE LOGS and ping the test owner."