Test explorer disappears every time a test file is saved

[MetRonnie]

Type: Bug

Behaviour

Every time a test file is saved, the test explorer now shows the "No tests have been found" view for a while until the pytest collection completes again.

Additionally, the icons in the gutter disappear and then start playing up when they reappear (trying to click the "run test" icon causes a breakpoint to be added, hovering over the gutter causes the gutter to change width).

This did not used to happen until recently (last fortnight or so).

Steps to reproduce:

1. Save a test 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)

XXX

Extension version: 2026.4.0
VS Code version: Code 1.120.0 (0958016b2af9f09bb4257e0df4a95e2f90590f9f, 2026-05-12T20:17:22Z)
OS version: Linux x64 5.14.0-611.54.1.el9_7.x86_64
Modes:

• Python version (& distribution if applicable, e.g. Anaconda): 3.14.4
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): Conda
• Value of the python.languageServer setting: Pylance

User Settings

languageServer: "Pylance"

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

Installed Extensions

Extension Name	Extension Id	Version
black-formatter	ms-	2026.6.0
copilot-chat	Git	0.48.1
debugpy	ms-	2026.6.0
even-better-toml	tam	0.21.2
flake8	ms-	2026.6.0
git-graph	mhu	1.30.0
github-vscode-theme	Git	6.3.5
gitlens	eam	18.3.0
isort	ms-	2026.7.12041004
jinjahtml	sam	0.20.0
js-debug	ms-	1.117.0
js-debug-companion	ms-	1.1.3
jsts-chat-features	Typ	0.0.2
jupyter	ms-	2025.9.1
jupyter-keymap	ms-	1.1.2
jupyter-renderers	ms-	1.3.0
python	ms-	2026.4.0
remote-explorer	ms-	0.5.0
remote-server	ms-	1.5.3
remote-ssh	ms-	0.124.0
ruff	cha	2026.68.0
shebang-language-associator	dav	1.4.0
shellcheck	tim	0.39.5
simple-rst	tro	1.5.4
sqlite-viewer	qwt	25.12.2
vscode-cylc	cyl	1.3.0
vscode-eslint	dba	3.0.34
vscode-github-actions	git	0.32.3
vscode-js-profile-table	ms-	1.0.10
vscode-jupyter-cell-tags	ms-	0.1.9
vscode-jupyter-slideshow	ms-	0.1.6
vscode-markdown-alert	yah	0.0.4
vscode-pull-request-github	Git	0.144.0
vscode-pylance	ms-	2026.3.1
vscode-python-envs	ms-	1.36.0
vscode-yaml	red	1.24.0

System Info

Item	Value
CPUs	AMD EPYC 7763 64-Core Processor (4 x 0)
GPU Status	2d_canvas: unavailable_software GPU0: VENDOR= 0xffff [Google Inc. (Google)], DEVICE=0xffff [ANGLE (Google, Vulkan 1.3.0 (SwiftShader Device (Subzero) (0x0000C0DE)), SwiftShader driver-5.0.0)], DRIVER_VENDOR=SwANGLE, DRIVER_VERSION=5.0.0 ACTIVE Machine model name: Machine model version: direct_rendering_display_compositor: disabled_off_ok gpu_compositing: disabled_software multiple_raster_threads: enabled_on opengl: disabled_off rasterization: disabled_software raw_draw: disabled_off_ok skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: disabled_software video_encode: disabled_software vulkan: disabled_off webgl: unavailable_software webgl2: unavailable_software webgpu: disabled_off webnn: unavailable_software
Load (avg)	2, 2, 2
Memory (System)	15.31GB (8.64GB free)
Process Argv
Screen Reader	no
VM	0%
DESKTOP_SESSION	gnome
XDG_CURRENT_DESKTOP	GNOME
XDG_SESSION_DESKTOP	undefined
XDG_SESSION_TYPE	x11

[Sawy7]

I can confirm this is an issue for me as well