locale.Error: unsupported locale setting

[hiddenslave]

Issue Type: Bug

File "/root/.vscode-server-insiders/extensions/ms-python.python-2020.1.58038/pythonFiles/lib/python/new_ptvsd/no_wheels/ptvsd/launcher/main.py", line 78, in
locale.setlocale(locale.LC_ALL, "")
File "/usr/lib/python3.6/locale.py", line 598, in setlocale
return _setlocale(category, locale)
locale.Error: unsupported locale setting

Extension version: 2020.1.58038
VS Code version: Code - Insiders 1.42.0-insider (960cddb992cc96d47f56b633b361909f1b5b3353, 2020-01-10T06:48:04.971Z)
OS version: Linux x64 5.3.0-26-generic
Remote OS version: Linux x64 5.3.0-26-generic

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz (4 x 2112)
GPU Status	2d_canvas: unavailable_software flash_3d: unavailable_off flash_stage3d: unavailable_off flash_stage3d_baseline: unavailable_off gpu_compositing: unavailable_off multiple_raster_threads: enabled_on oop_rasterization: unavailable_off protected_video_decode: unavailable_off rasterization: unavailable_off skia_renderer: disabled_off_ok video_decode: unavailable_off viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled_readback webgl2: unavailable_off
Load (avg)	0, 1, 1
Memory (System)	17.24GB (11.74GB free)
Process Argv	--no-sandbox --unity-launch
Screen Reader	no
VM	40%

Item	Value
Remote	Dev Container: Existing Docker Compose …
OS	Linux x64 5.3.0-26-generic
CPUs	Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz (4 x 2112)
Memory (System)	17.24GB (11.74GB free)
VM	0%

[int19h]

It sounds like your container has LANG or some of the LC_* environment variables set to a specific locale, but that locale isn't actually supported by the OS running inside the container.

If you expect the locale to be set, make sure that it's generated - sudo locale-gen should do the trick. If you deliberately removed the locales to save space, you need to ensure that environment variables reflect that.