[scss] inbuild sass/scss extension shows error that is none

[capoaira]

Type: Bug

The provided code shows errors from scss(css-rcurlyexpected) but will be compiled and work as expected

// Mixin for slide animations
@mixin slideX($from, $to) {
  0% {
    transform: translateX($from);
  }
  100% {
    transform: translateX($to);
  }
}

// Animations using the mixins
@keyframes slide-left {
  @include slideX(0, -100%);
}

@keyframes slide-right {
  @include slideX(-100%, 0);
}

I think it's a problem with the inbuild sass/scss extesions. The original repo for this is archived, so I report it here.

VS Code version: Code 1.92.2 (fee1edb, 2024-08-14T17:29:30.058Z)
OS version: Linux x64 6.8.0-40-generic
Modes:

System Info

Item	Value
CPUs	13th Gen Intel(R) Core(TM) i5-13600K (20 x 5100)
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: disabled_software vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off webnn: disabled_off
Load (avg)	1, 0, 0
Memory (System)	31.12GB (26.81GB free)
Process Argv	/home/jannes/git/Leaflet.SidePanel --crash-reporter-id 1b52595c-35cb-48ee-8645-6520db63350d
Screen Reader	no
VM	0%
DESKTOP_SESSION	cinnamon
XDG_CURRENT_DESKTOP	X-Cinnamon
XDG_SESSION_DESKTOP	cinnamon
XDG_SESSION_TYPE	x11

Extensions (20)

Extension	Author (truncated)	Version
vscode-intelephense-client	bme	1.12.5
vscode-eslint	dba	3.0.10
prettier-vscode	esb	11.0.0
copilot	Git	1.224.0
copilot-chat	Git	0.18.2
vscode-github-actions	git	0.26.3
todo-tree	Gru	0.0.226
vscode-language-pack-de	MS-	1.92.2024081409
java	red	1.34.0
format-html-in-php	rif	1.7.0
pdf	tom	1.2.2
intellicode-api-usage-examples	Vis	0.2.8
vscodeintellicode	Vis	1.3.1
vscode-gradle	vsc	3.16.4
vscode-java-debug	vsc	0.58.0
vscode-java-dependency	vsc	0.24.0
vscode-java-pack	vsc	0.29.0
vscode-java-test	vsc	0.42.0
vscode-maven	vsc	0.44.0
volar	Vue	2.1.4

A/B Experiments

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binariesv615:30325510
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py29gd2263:31024239
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azure-dev_surveyone:30548225
962ge761:30959799
pythongtdpath:30769146
pythonnoceb:30805159
asynctok:30898717
pythonregdiag2:30936856
pythonmypyd1:30879173
h48ei257:31000450
pythontbext0:30879054
dsvsc016:30899300
dsvsc017:30899301
dsvsc018:30899302
cppperfnew:31000557
dsvsc020:30976470
pythonait:31006305
dsvsc021:30996838
9c06g630:31013171
pythoncenvpt:31062603
a69g1124:31058053
dvdeprecation:31068756
dwnewjupytercf:31046870
newcmakeconfigv2:31071590
impr_priority:31102340
nativerepl1:31104043
refactort:31108082
pythonrstrctxt:31112756
wkspc-onlycs-t:31111718
wkspc-ranged-c:31125598
fje88620:31121564
aajjf12562:31125793

[kakiuwang-ui]

This comes from the SCSS parser in vscode-css-languageservice: keyframe selectors like 0% / 100% were only accepted in a couple of special-cased contexts, so @mixin declaration bodies raise false css-rcurlyexpected errors even though the Sass compiles fine.

I've opened microsoft/vscode-css-languageservice#502 which fixes this for SCSS mixin bodies (including keyframe selectors nested under @if/@each/@for) as well as the equivalent case in LESS parametric mixins.

[lszomoru]

I am still able to repro with the latest VS Code Insiders

Version: 1.135.0-insider
Commit: 0052619e71feb774a574b37f4f2ea20c36547373
Date: 2026-08-23T20:50:57-07:00
Electron: 42.8.1
ElectronBuildId: 14906494
Chromium: 148.0.7778.280
Node.js: 24.18.1
V8: 14.8.178.38-electron.0
@github/copilot: 1.0.81-0
@github/copilot-sdk: 1.0.11
OS: Darwin arm64 25.6.0