Vite "[vite:css]" - Fix CSS/PostCSS Build Errors in CI

By Daniel Zoghalchali·Latchkey

The vite:css plugin failed while transforming a stylesheet. The cause is in the CSS pipeline - a PostCSS/Sass plugin throwing, a syntax error in the stylesheet, or an @import/url() that does not resolve.

What this error means

The build fails with a [vite:css] error naming the stylesheet and the underlying failure. It can be a parse error, a missing PostCSS plugin, or an unresolved import referenced from CSS.

[vite:css] Failed to load PostCSS config: Cannot find module 'autoprefixer'
file: /app/src/styles/main.css
    at Object.<anonymous> (postcss.config.js:3:18)
error during build:

Common causes

A PostCSS/Sass plugin throws or is missing

A plugin referenced in postcss.config.js (or a Sass feature) is not installed or errors on the input, so the CSS transform fails.

Syntax error in the stylesheet

A malformed rule, an unclosed brace, or an invalid at-rule makes the CSS parser throw during the transform.

Unresolved @import or url() asset

A CSS @import or url() points at a file that does not exist (wrong path or case), which the CSS plugin cannot resolve at build time.

How to fix it

Install the missing CSS tooling

Add every PostCSS plugin your config references as a dev dependency.

npm install -D autoprefixer postcss
npm ls autoprefixer   # confirm it resolves

Read the underlying CSS error

1. The [vite:css] line wraps the real cause - read the message beneath it (parse error, missing module, unresolved import).
2. Fix the stylesheet syntax or correct the @import/url() path and case.
3. Confirm postcss.config.js only references installed plugins.

How to prevent it

• Declare every PostCSS/Sass plugin in devDependencies.
• Run vite build in CI so CSS-pipeline errors fail before deploy.
• Match @import/url() paths and casing to real files.

Frequently asked questions

Related guides

References

• Node.js documentation
• npm CLI documentation
• GitHub Actions documentation