Tailwind v4 "Cannot create proxy with a non-object as target or handler" after devinxi

[yjoer]

Which project does this relate to?

Start

Describe the bug

The reproduction is based on basic-virtual-file-based with my changes in the third commit yjoer/basic-virtual-file-based@9f291d9.

When building the application, the following error message arises.

[@tailwindcss/vite:generate:build] Cannot create proxy with a non-object as target or handler
file: /basic-virtual-file-based/src/styles.css?transform-only

Your Example Website or App

https://github.com/yjoer/basic-virtual-file-based

Steps to Reproduce the Bug or Issue

1. Run pnpm build

Expected behavior

Building the app without errors.

Screenshots or Videos

No response

Platform

• OS: Windows
• Browser: Chrome
• Version: 136

Additional context

No response

[schiller-manuel]

does this require virtual file based routing or is this also reproducable in start-basic example?

[yjoer]

I haven't checked on start-basic. I'll let you know in a while

[yjoer]

I did the same in the second commit yjoer/start-basic@703997f of start-basic. I can see the same error happening.

[@tailwindcss/vite:generate:build] Cannot create proxy with a non-object as target or handler
file: /start-basic/src/styles/app.css?transform-only

[yjoer]

The error only occurs during the build process on both repositories. Everything works fine on the development server.

[schiller-manuel]

fixed in https://github.com/TanStack/router/releases/tag/v1.120.4-alpha.16

[crrobinson14]

Not sure if I should revive this or post a new entry @schiller-manuel but I am on tsrouter 1.120.11 (past the fix above) and still seeing this exact error.

[@tailwindcss/vite:generate:build] Cannot create proxy with a non-object as target or handler
file: [REDACTED]/apps/web/src/index.css

[yjoer]

I couldn't reproduce this on the alpha release. Perhaps, the regression only affects the mainline.

[crrobinson14]

Please disregard my comment. I was thrown off by the precise match of the error message and circumstance. But when reproducing the issue I found that removing tanstack-router had no effect. It appears to be the same issue already solved here (Vite Environments API breaking change) but also affecting Cloudflare's Workers SDK as well. I cross-linked the two above and I think it's just another affected library.