pytest doubles %PYTHONPATH% in a debug run

[schperplata]

Issue Type: Bug

If %PYTHONPATH% is set, VSC test (pytest) plugin double %PYTHONPATH% in debug configuration. Not the case with run configuration.

Example (run):

test_example.py::test_printPythonPath 
%PYTHONPATH%:
	 PYTHONPATH_ENV_VAR
PASSED

Example (debug):

test_example.py::test_printPythonPath 
%PYTHONPATH%:
	 PYTHONPATH_ENV_VAR
	 PYTHONPATH_ENV_VAR
PASSED

Doesn't really affect my use case, but I consider this as a bug.

Extension version: 2020.8.105045
VS Code version: Code 1.48.2 (a0479759d6e9ea56afa657e454193f72aef85bd0, 2020-08-25T10:13:11.295Z)
OS version: Windows_NT x64 10.0.19041

System Info

Item	Value
CPUs	Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz (4 x 3193)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	15.89GB (6.95GB free)
Process Argv	vsCodeTest.code-workspace
Screen Reader	no
VM	0%

[karrtikr]

@schperplata I can reproduce this when I set environment variables using .env file, and print environment variables to file, thanks! Btw how were you setting environment variables?

[schperplata]

In this specific case, I have a .bat file that set PYTHONPATH and open VSC workspace. I figured out this is the simplest way of configuring VSC workspace without mulitplying source paths for pylint, pylance, autocomplete, ...
Anyway, I don't know if that happened before when we also used .env files.