Conda environment initialized differently when executing vs debugging unit tests

[dobos]

I have to develop my code on a custom python stack that doesn't fully conform to anaconda; many packages are initialized by adding them to PYTHONPATH with a command-line tool. I automated this by creating an activation script that went under etc/conda/activate.d. I also have a .env in the workspace root that sets the same PYTHONPATH. I works but I found the following issue:

• When a unit test is started without debugging the procedure of running it is: 1) source .env 2) execute conda run ... which will result in sourcing the custom activation scripts under etc/conda/activate.d.
• When a unit test is started in the debugger, the procedure differs: 1) source .env 2) execute some auto-generated script that will call the debugpy module. The custom activation scripts under etc/conda/activate.d seem not be sourced.

This can be an issue for some. The behavior should be that the conda environment is activated the same way while debugging and just executing unit tests.

[eleanorjboyd]

Hi! A few questions, when you say debugging a unit test are you doing this through the UI in the test explorer or are you building a launch.json config? Secondly can you check if the cwd differs for either run? Like in the tests have it print the cwd and this should tell us if one of them is getting edited or changed.

[dobos]

Here are the outputs from various tasks. This project folder doesn't have a launch.config. To run/debug, I just clicked on the icons in test view. The debug command is not written to the Python output but rather to the Python Debugging output. This is a simple project I put together for this purpose and I didn't check if it shows the same behavior as the large project but as far as I can tell from the logs, the actual Python commands that are executed a different for run/debug. When clicking on Run, the python command is called as conda run -p ... python ..., when clicking on debug, the python debugpy adapter is called directly as python ..., see the last log file. I think conda activation scripts are not run in the latter case.

Test discovery

2025-07-01 12:51:08.413 [info] Discover tests for workspace name: pydebugtest - uri: /home/dobos/tmp/pydebugtest
2025-07-01 12:51:08.424 [info] Discovering unittest tests for workspace /home/dobos/tmp/pydebugtest with arguments: /home/dobos/.vscode-server/extensions/ms-python.python-2025.8.0-linux-x64/python_files/unittestadapter/discovery.py,--udiscovery,-v,-s,test/pydebugtest,-p,test_*.py

2025-07-01 12:51:08.431 [info] > /miniconda3/bin/conda run -p /miniconda3/envs/dobos-torch --no-capture-output python ~/.vscode-server/extensions/ms-python.python-2025.8.0-linux-x64/python_files/get_output_via_markers.py ~/.vscode-server/extensions/ms-python.python-2025.8.0-linux-x64/python_files/unittestadapter/discovery.py --udiscovery -v -s test/pydebugtest -p test_*.py
2025-07-01 12:51:08.431 [info] cwd: .
2025-07-01 12:51:09.604 [info] >>>PYTHON-EXEC-OUTPUT

2025-07-01 12:51:09.652 [info] <<<PYTHON-EXEC-OUTPUT

Running a test

2025-07-01 12:49:55.854 [info] Running UNITTEST execution for the following test ids: test_pydebugclass.TestPyDebugClass.test_init
2025-07-01 12:49:55.854 [info] Attempting to use temp directory for test ids file, file name: test-ids-2ede9e956a231003ec1d.txt
2025-07-01 12:49:55.855 [info] All environment variables set for unittest execution, PYTHONPATH: "/home/dobos/tmp/pydebugtest:/home/dobos/tmp/pydebugtest/python"
2025-07-01 12:49:55.868 [info] Running unittests for workspace /home/dobos/tmp/pydebugtest with arguments: /home/dobos/.vscode-server/extensions/ms-python.python-2025.8.0-linux-x64/python_files/unittestadapter/execution.py,--udiscovery,-v,-s,test/pydebugtest,-p,test_*.py

2025-07-01 12:49:55.868 [info] > /miniconda3/bin/conda run -p /miniconda3/envs/dobos-torch --no-capture-output python ~/.vscode-server/extensions/ms-python.python-2025.8.0-linux-x64/python_files/get_output_via_markers.py ~/.vscode-server/extensions/ms-python.python-2025.8.0-linux-x64/python_files/unittestadapter/execution.py --udiscovery -v -s test/pydebugtest -p test_*.py
2025-07-01 12:49:55.868 [info] cwd: .
2025-07-01 12:49:57.143 [info] Test Result named pipe /run/user/1897/python-test-results-011ff6e137a60be0afe7  cancelled

Debugging a test

2025-07-01 12:51:32.300 [info] Running UNITTEST execution for the following test ids: test_pydebugclass.TestPyDebugClass.test_init
2025-07-01 12:51:32.300 [info] Attempting to use temp directory for test ids file, file name: test-ids-3458cada3154645ed446.txt
2025-07-01 12:51:32.302 [info] All environment variables set for unittest execution, PYTHONPATH: "/home/dobos/tmp/pydebugtest:/home/dobos/tmp/pydebugtest/python"
2025-07-01 12:51:32.302 [info] Running DEBUG unittest for workspace /home/dobos/tmp/pydebugtest with arguments: /home/dobos/.vscode-server/extensions/ms-python.python-2025.8.0-linux-x64/python_files/unittestadapter/execution.py,--udiscovery,-v,-s,test/pydebugtest,-p,test_*.py

2025-07-01 12:51:32.302 [info] Using configuration in workspace
2025-07-01 12:51:37.676 [info] Test Result named pipe /run/user/1897/python-test-results-60e41a95b3d7afeb5061  cancelled

And this is what appears in the Python Debugger output:

2025-07-01 12:56:53.680 [info] Resolving launch configuration with substituted variables
2025-07-01 12:56:54.196 [info] DAP Server launched with command: /miniconda3/envs/dobos-torch/bin/python /home/dobos/.vscode-server/extensions/ms-python.debugpy-2025.8.0-linux-x64/bundled/libs/debugpy/adapter
2025-07-01 12:56:54.532 [info] Received 'debugpySockets' event from debugpy.
2025-07-01 12:56:54.964 [info] Received 'debugpySockets' event from debugpy.
2025-07-01 12:56:54.964 [info] Received 'debugpySockets' event from debugpy.
2025-07-01 12:56:55.334 [info] Received 'debugpySockets' event from debugpy.
2025-07-01 12:56:56.833 [info] Received 'debugpySockets' event from debugpy.
2025-07-01 12:56:57.095 [info] Received 'debugpySockets' event from debugpy

[dobos]

I set up the full environment, with user script under etc/conda/activate.d. I simply set the value of an environmental variable from the activation script. When I run the unit test, it sees the variable, when I debug it, the variable is not in os.environ. I do not have a launch.json file in the workspace.