This might go beyond what you were asking for, but I’m always more comfortable handling file paths, deletions and errors in Python.

#!/usr/bin/env python3

import shutil
from pathlib import Path
from tempfile import TemporaryDirectory

# Refuse to run without Python's symlink-resistant cleanup.
if not getattr(shutil.rmtree, "avoids_symlink_attacks", False):
    raise RuntimeError("Symlink-resistant cleanup is unavailable")

with TemporaryDirectory(prefix="test-run-", dir="/tmp") as name:
    tests = Path(name) / "tests"
    tests.mkdir(mode=0o700)
    print(f"Created {str(tests)!r}", flush=True)

    try:
        # Put your test code here.
        (tests / "example.txt").write_text(
            "temporary data\n", encoding="utf-8"
        )
    finally:
        print(f"Cleaning {name!r}", flush=True)

# The entire temporary directory has now been removed.