Error selecting Python virtual environment ("Failed to resolve env")

[pzelnip]

Type: Bug

Behaviour

When I pick "Python: Select Interpreter" from the command pallette and then pick "Use Python from python.defaultInterpreterPath setting" I get a failed to resolve error: https://cdn.zappy.app/2af8899b7bd3748f8d924a85cd760381.png

This seems to happen on all my projects. Probably worth noting: all my projects use poetry and store the virtual environment in a .venv directory that is not at the top level of the project.

Possibly related to !25190 If I symlink my .venv directory to venv (no period), then I have the option to select my virtual environment as a workspace option and it seems to select correctly.

FWIW, the entry I have in settings.json for defaultInterpreterPath is:

"python.defaultInterpreterPath": "web/backend/.venv/bin/python",

On other projects (where I get the same error) that path varies a bit, but generally is always somedirectory/.venv/bin/python

Steps to reproduce:

1. pick "Python: Select Interpreter" from the command pallette
2. pick "Use Python from python.defaultInterpreterPath setting"
3. see error

Diagnostic data

In the Python logs I see:

2025-07-28 13:21:42.538 [error] Python Extension: sendTelemetry l [Error]: Failed to resolve env "/web/backend/.venv/bin/python"
    at se (/Users/adamparkin/.vscode/extensions/ms-python.vscode-python-envs-1.2.0-darwin-arm64/dist/extension.js:2:572709)
    at ae (/Users/adamparkin/.vscode/extensions/ms-python.vscode-python-envs-1.2.0-darwin-arm64/dist/extension.js:2:570669)
    at Immediate.<anonymous> (/Users/adamparkin/.vscode/extensions/ms-python.vscode-python-envs-1.2.0-darwin-arm64/dist/extension.js:2:566963)
    at processImmediate (node:internal/timers:485:21) {
  code: -4,
  data: undefined
}

Extension version: 2025.10.1
VS Code version: Code 1.102.1 (Universal) (7adae6a56e34cb64d08899664b814cf620465925, 2025-07-15T16:41:17.147Z)
OS version: Darwin arm64 24.5.0
Modes:

• Python version (& distribution if applicable, e.g. Anaconda): 3.13.4.final.0
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): System
• Value of the python.languageServer setting: Pylance

User Settings

venvPath: "<placeholder>"

languageServer: "Pylance"

testing
• pytestArgs: "<placeholder>"
• pytestEnabled: true
• unittestArgs: "<placeholder>"

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avro	str	0.5.0
better-comments	aar	3.0.2
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change-case	wma	1.0.0
code-runner	for	0.12.2
code-spell-checker	str	4.0.47
codesnap	adp	1.3.4
copilot	Git	1.346.0
copilot-chat	Git	0.29.1
copy-markdown-as-html	jer	1.1.0
debugpy	ms-	2025.10.0
django-html	bib	1.3.0
djlint	mon	2025.5.0
EditorConfig	Edi	0.17.4
emojisense	bie	0.10.0
even-better-toml	tam	0.21.2
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gitlab-workflow	Git	6.35.0
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js-debug	ms-	1.102.0
js-debug-companion	ms-	1.1.3
jupyter	ms-	2025.6.0
jupyter-keymap	ms-	1.1.2
jupyter-renderers	ms-	1.3.0
jwt-decoder	jfl	1.2.0
kitty-time	QzS	0.5.2
live-server	ms-	0.4.15
mako	tom	0.2.0
markdown-all-in-one	yzh	3.6.3
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mypy-type-checker	ms-	2025.2.0
partial-diff	ryu	1.4.3
presentationmode	jsp	1.1.5
prettier-vscode	esb	11.0.0
pylint	ms-	2025.2.0
python	ms-	2025.10.1
python-environment-manager	don	1.2.7
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remote-wsl	ms-	0.99.0
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ruff	cha	2025.24.0
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vscode-base64	ada	0.1.0
vscode-containers	ms-	2.1.0
vscode-coverage-gutters	rya	2.13.0
vscode-djaneiro	the	1.4.2
vscode-docker	ms-	2.0.0
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vscode-faker	dee	2.0.0
vscode-fileutils	sle	3.10.3
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vscode-htmlhint	HTM	1.11.1
vscode-icons	vsc	12.13.0
vscode-javascript-booster	sbu	14.0.1
vscode-js-profile-table	ms-	1.0.10
vscode-jupyter-cell-tags	ms-	0.1.9
vscode-jupyter-slideshow	ms-	0.1.6
vscode-markdownlint	Dav	0.60.0
vscode-pets	ton	1.32.0
vscode-postgres	cko	1.4.3
vscode-pull-request-github	Git	0.114.3
vscode-pylance	ms-	2025.7.1
vscode-python-envs	ms-	1.2.0
vscode-random	jre	1.12.0
vscode-remote-extensionpack	ms-	0.26.0
vscode-spotify	shy	3.2.1
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System Info

Item	Value
CPUs	Apple M4 Pro (14 x 2400)
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: enabled_on video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	5, 4, 3
Memory (System)	48.00GB (6.69GB free)
Process Argv	/Users/adamparkin/temp/sandbox/zapstorage --crash-reporter-id 7c29673d-541b-4c7d-8598-75a70ed69912
Screen Reader	no
VM	0%

A/B Experiments

vsliv368cf:30146710
binariesv615:30325510
h48ei257:31000450
nativeloc1:31344060
dwcopilot:31170013
6074i472:31201624
dwoutputs:31242946
9064b325:31222308
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
9d2cg352:31346308
convertlamdaf:31350062
usemarketplace:31343026
nesew2to5:31336538
agentclaude:31350858
b6b4d950:31327385
nes-diff-11:31337487
replacestringexc:31350595
nes-set-on:31351930
onetestforazureexpcf:31335614
6abeh943:31336334
envsactivate1:31353494
yijiwantestdri0626-c:31336931
0927b901:31350571
4gdec884:31348710
45650338:31356125
0cj2b977:31352657

[eleanorjboyd]

Thank you for the detailed issue- I will investigate!

[pzelnip]

This has regressed further for me, now even though I have "python.terminal.activateEnvironment": true, in my settings, upon opening the integrated terminal the selected interpreter's environment is not activated.

Compounding this is the fact it seems like now the only way to view settings is via UI? What happened to the button to toggle between the UI view of settings and viewing settings as raw JSON?

[pzelnip]

Interestingly disbling the newer Python Environments extension fixed all of these issues for me.

[eleanorjboyd]

Hi so sorry- this must be a problem with our environments extension. I will transfer it over there to investigate further.

I would also like to apologize for the delay on getting back to you on this issue, I appreciate users taking the time to write bug reports and update them and have many bugs coming in from the new extension I have had to prioritize. Thank you for your patience!

[eleanorjboyd]

Ok so for the issue with not seeing the button, it should be here
which I see on your screenshot maybe just in a different place than you expected?

Secondly can you try doing the following:

1. enable the python environments extension
2. run the command palette command "Python: Run Python Environment Tool (PET) in Terminal"
3. You should see something like this output in the console: /Users/eleanorboyd/.vscode-insiders/extensions/ms-python.vscode-python-envs-1.3.12131645-darwin-arm64/python-env-tools/bin/pet" which is the path to the PET executable
4. take this path, and do the following like this: /Users/eleanorboyd/.vscode-insiders/extensions/ms-python.vscode-python-envs-1.3.12131645-darwin-arm64/python-env-tools/bin/pet resolve web/backend/.venv/bin/python and let me know the result.

I think your interpreter is web/backend/.venv/bin/python but I also saw in the notification screenshot you sent it is /backend/.venv/bin/python? Let me know which one / try it both ways would be great- thanks!

[github-actions]

Because we have not heard back with the information we requested, we are closing this issue for now. If you are able to provide the info later on, then we will be happy to re-open this issue to pick up where we left off.

Happy Coding!

[terese-cavaggioni]

I recently ran into this issue which led me to this page. Disabling the extension resolved the issue, and I re-enabled + followed the resolution steps (I just chose the Resolve Option from the 2 listed). That did the trick so I wanted to leave this comment for anyone else who stumbles on this.