Can you add a test where uv check fails?

I think it's hard.

• Package installation already checks conflicts, checkout

  ray/python/ray/tests/test_runtime_env_conda_and_pip_5.py

  Lines 63 to 89 in 0251a3e

  	def test_runtime_env_cache_with_pip_check(start_cluster):
  	# moto require requests>=2.5
  	conflict_packages = ["moto==3.0.5", "requests==2.4.0"]
  	runtime_env = {
  	"pip": {
  	"packages": conflict_packages,
  	"pip_version": "==20.2.3",
  	"pip_check": False,
  	}
  	}
  	@ray.remote
  	def f():
  	return True
  	assert ray.get(f.options(runtime_env=runtime_env).remote())
  	runtime_env["pip"]["pip_version"] = "==21.3.1"
  	# Just modify filed pip_version, but this time,
  	# not hit cache and raise an exception
  	with pytest.raises(ray.exceptions.RuntimeEnvSetupError) as error:
  	ray.get(f.options(runtime_env=runtime_env).remote())
  	assert "The conflict is caused by:" in str(error.value)
  	assert "The user requested requests==2.4.0" in str(error.value)
  	assert "moto 3.0.5 depends on requests>=2.5" in str(error.value)

• The only way I could think of faking and testing pip_check failure, is you download a series of compatible packages, enter into the virtual environment and modify the packages manually
• I don't think it's viable based on our current test setup, since everything's constructed and destructed when ray.remote finishes, which you don't have a way to hack in