Test window stops updating

[ssorgl]

Issue Type: Bug

It is not entirely clear to me what the actual trigger for this is - it just happens after a time...

1. Open a Python project with tests
2. Discover all tests
3. Run all tests
   still working fine. Seem to be able to run all tests multiple times
4. Select a single test and debug it - stepping through, possibly multiple times. Sometimes using the call stack to look at variables at different levels. Watch window has variables not always in scope - some of which would likely throw an exception (i.e. self.attr.sub_attr - asn self does not always exist).

At some point while doing this, the test window no longer updates. I can still click on the bug icon or the run icon to run the test - but it does not show the results. Also, cannot click on the document icon to show the test in the main window.

Hitting the 'test discovery' icon at the top runs discovery, but does not update the window. Run all tests from the icon at the top of the window runs the tests but does not update the window.

Extension version: 2020.3.71659
VS Code version: Code 1.44.0 (2aae1f26c72891c399f860409176fe435a154b13, 2020-04-08T08:23:56.137Z)
OS version: Darwin x64 19.4.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz (12 x 2600)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off 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)	2, 2, 2
Memory (System)	32.00GB (11.69GB free)
Process Argv	-psn_0_155686
Screen Reader	no
VM	0%

[int19h]

Judging by the mention of Watch expressions that sometimes produce errors, this sounds a lot like microsoft/debugpy#108. The fix for that should be in the next insiders build of the extension.