Code debugging starts before conda env activates

[Sunlight-zero]

Type: Bug

Behaviour

When trying to debug a .py file in conda environment on Windows 11, the debugger runs the python file before conda activate <env>.

In detail, there are two conda activating commands that the Python extension will automatically run:

<conda env path>/Scripts/activate
conda activate <env name>

But when debugging a Python code, the debugger starts after <conda env path>/Scripts/activate but before conda activate <env name>, which may cause some incorrect environment settings, like a wrong PATH and cannot find dynamic link libraries.

Steps to reproduce:

1. Ensure conda has been installed.
2. Select a conda environment's python exe as the python interpreter for .py
3. Debug a .py file.

Diagnostic data

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

PS D:\program\Python\auto-workflows> D:/program/Python/anaconda/envs/math_model/Scripts/activate
PS D:\program\Python\auto-workflows>  & 'd:\program\Python\anaconda\envs\workflow\python.exe' 'c:\Users\Sunlight\.vscode\extensions\ms-python.debugpy-2025.10.0-win32-x64\bundled\libs\debugpy\launcher' '8419' '--' 'd:\program\Python\auto-workflows\helloworld.py' 
Hello World
PS D:\program\Python\auto-workflows> conda activate workflow
(workflow) PS D:\program\Python\auto-workflows> 

Extension version: 2025.11.2025072501
VS Code version: Code 1.102.2 (c306e94f98122556ca081f527b466015e1bc37b0, 2025-07-22T12:15:48.520Z)
OS version: Windows_NT x64 10.0.26100
Modes:

System Info

Item	Value
CPUs	12th Gen Intel(R) Core(TM) i7-12700H (20 x 2688)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	15.63GB (3.50GB free)
Process Argv	--crash-reporter-id 59651958-9740-4efc-af64-7724da49518f
Screen Reader	no
VM	50%

A/B Experiments

vsliv368cf:30146710
pythonvspyt551:31249599
binariesv615:30325510
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nativeloc1:31344060
dwcopilot:31170013
6074i472:31201624
dwoutputs:31242946
hdaa2157:31222309
copilot_t_ci:31333650
e5gg6876:31282496
pythoneinst12:31285622
c7cif404:31314491
pythonpulldiag:31343502
996jf627:31283433
pythonrdcb7:31342333
usemplatestapi:31297334
0aa6g176:31307128
747dc170:31275177
aj953862:31281341
generatesymbolt:31295002
convertfstringf:31295003
pylancequickfixt:31350061
9d2cg352:31346308
convertlamdat:31350063
usemarketplace:31343026
nesew2to5:31336538
agentclaude:31350858
nes-diff-11:31337487
replacestringexc:31350595
nes-set-on:31351930
testaa123:31335226
6abeh943:31336334
yijiwantestdri0626-t:31336930
0927b901:31350571
ji9b5146:31348712
0cj2b977:31352657
0574c672:31355360

[yonaroz]

I experience a similar issue on linux which causes the debugger to sometimes run before my .zshrc file. This file also contains my conda init logic and therefore causes similar issue.

[eleanorjboyd]

Hi! Can you check to see if the behavior changes if you disable the "Python Environments Extension?"?

[yonaroz]

TL;DR Disabling the Powerlevel10k Instant Prompt feature resolved the issue for me.

In my case, the issue was caused by the Instant Prompt feature of Powerlevel10k. It seems that this feature caused my .zshrc to execute in a non-blocking way, allowing subsequent Zsh commands (such as debugging) to run before it finished. I also noticed that sometimes the conda environment attempted to activate before the .zshrc init code had fully run, which also led me to suspect that my .zshrc wasn’t blocking as expected.

[Sunlight-zero]

Hi! Can you check to see if the behavior changes if you disable the "Python Environments Extension?"?

No. After disabling Python Environments Extension, the problem still exists.

PS D:\program\Python\auto-workflows> D:/program/Python/miniconda/Scripts/activate
PS D:\program\Python\auto-workflows>  & 'd:\program\Python\anaconda\envs\workflow\python.exe' 'c:\Users\Sunlight\.vscode\extensions\ms-python.debugpy-2025.10.0-win32-x64\bundled\libs\debugpy\launcher' '8663' '--' 'd:\program\Python\auto-workflows\helloworld.py' 
Hello World
PS D:\program\Python\auto-workflows> conda activate workflow
(workflow) PS D:\program\Python\auto-workflows> 

[eleanorjboyd]

@Sunlight-zero are you using something similar to @yonaroz like Powerlevel10k Instant Prompt?

cc @anthonykim1

[Sunlight-zero]

@eleanorjboyd I have disabled or uninstalled all other plugins and left Python and Python Debugger only, but the problem still exists.

PS D:\program\Python\auto-workflows> D:/program/Python/miniconda/Scripts/activate
PS D:\program\Python\auto-workflows>  & 'd:\program\Python\anaconda\envs\workflow\python.exe' 'c:\Users\Sunlight\.vscode\extensions\ms-python.debugpy-2025.10.0-win32-x64\bundled\libs\debugpy\launcher' '2612' '--' 'd:\program\Python\auto-workflows\helloworld.py' 
Hello World
PS D:\program\Python\auto-workflows> conda activate workflow
(workflow) PS D:\program\Python\auto-workflows>