pytest 5.1.0 seems to break the test adapter

Issue Type: Bug

After updating VSCode from v1.36.1 to v1.37.1 (in WSL), pytest unit tests are no longer displaying green/red status in the side bar. An error pop-up is displayed with the following message:

There was an error in running the tests. Source Python (Extension)

The OUTPUT tab indicates that the test passed, but there is also an error message that seems like it is related to the extension issue:

============================= test session starts ==============================
platform linux -- Python 3.6.8, pytest-5.1.0, py-1.8.0, pluggy-0.12.0
rootdir: /mnt/c/Users/.../
plugins: cov-2.7.1
collected 1 item

tests/test___init__.py .                                                 [100%]

-------------- generated xml file: /tmp/tmp-2499XLU6ay233ncl.xml ---------------
============================== 1 passed in 0.06s ===============================
Error: TypeError: Cannot read property '$' of undefined

Extension version: 2019.8.30787 VS Code version: Code 1.37.1 (f06011ac164ae4dc8e753a3fe7f9549844d15e35, 2019-08-15T16:17:55.855Z) OS version: Windows_NT x64 10.0.17134 Remote OS version: Linux x64 4.4.0-17134-Microsoft

System Info

Item	Value
CPUs	Intel® Xeon® CPU X5650 @ 2.67GHz (12 x 3800)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: enabled skia_deferred_display_list: disabled_off skia_renderer: disabled_off surface_synchronization: enabled_on video_decode: enabled viz_display_compositor: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	24.00GB (14.93GB free)
Process Argv	–folder-uri=vscode-remote://wsl+default/mnt/c/Users/…/ --remote=wsl+default
Screen Reader	no
VM	50%

Item	Value
Remote	WSL
OS	Linux x64 4.4.0-17134-Microsoft
CPUs	Intel® Xeon® CPU X5650 @ 2.67GHz (12 x 3800)
Memory (System)	24.00GB (14.93GB free)
VM	50%

[ericsnowcurrently]

@krazyace78, thanks for letting us know about this. It looks like pytest 5.1.0 changed something in their XML output. We’ll get this fixed as soon as we can.

[marsfan]

Upon further examination, the output between 5.1.0 and 5.0.1 seems to be the same, so I do not know why this would trigger an error, but I know that downgrading to 5.0.1 fixed it for me.