This is a demonstration of CPP-33397 that effects CLion pytest run configurations. CLion builds a local index of header files used by a project for use with its various code assistance features. These files can be seen in the Header Search Paths section of the Project window content pane.
The problem is that all of these paths are being injected into the Python environment used to run pytest configurations (and presumably all Python run configurations). Consider a project that uses a Docker toolchain for C++ development and a local Python virtualenv environment for various project management tasks, such as integration tests written using pytest. The local Python environment should be completely isolated from the Docker toolchain environment.
In the real-world project where this bug was discovered, importing urllib3
in a pytest module was failing when the module was run from CLion. This same
module runs successfully from the command line using the local Python virtualenv.
The urllib3.response module optionally uses the brotli module if it is
available in the Python environment. The local pytest environment does not
have the brotli Python library installed, but the Docker image used as the
C++ toolchain does have the brotli C library headers installed. CLion
includes this path (/urs/include/brotli) when it runs pytest, and Python
interprets this is as a namespace package. Thus, urllib3 thinks brotli
is installed and fails when trying to use it.
Create the local development environment, including a Docker image to use as a CLion C++ toolchain (Docker Engine must be running locally):
$ make dev
Execute pytest from the command line. All tests should pass.
$ make test
Open the project in CLion. Set up a C++ toolchain using the clion-pytest-bug:latest
Docker image. Once CLion has finished indexing the project, verify that brotli
is listed as one of the Header Search Paths in the Project tool window.
Set the local Python virtualenv (.venv/) as the CLion Python interpreter.
Create a pytest run configuration to execute test_pytest.py using this
interpreter. Run the configuration; the test suite will fail. Use the debugger
to see that the value of brotli.__path__ is the cached include path from
the C++ toolchain.
To reproduce the original bug from the real-world project where this was
discovered, install urllib3 into the local virtualenv and attempt to import
it in test_pytest.py.
Add this before any imports in a local Python script that needs to be executed using CLion. This will remove the cached remote headers from the Python import search path.
""" Script that runs as a Python Run Configuration in CLion.
"""
# Remove CLion remote toolchain header caches from the module search path to
# prevent discovery by the local Python interpreter, which could result in
# false positives on import.
# <https://youtrack.jetbrains.com/issue/CPP-33397>
import sys
sys.path = [item for item in sys.path if "Caches/JetBrains/CLion" not in item]
# Normal script imports go here.