"Could not load css"

[nickretallack]

Describe the bug

If you generate a new remix app and upgrade to vite@6 and run remix vite:dev, it has a problem with loading CSS files on the server side. It will print
Could not load /Users/me/my-remix-app/app/tailwind.css to the console and the page will initially display unstyled, but then it will load the CSS file eventually anyway. This proves that it can see the file, but is having some sort of problem in the initial server side rendering. It works fine with vite@5 so this is a regression.

The repro steps are very simple so I don't think a reproduction link is necessary. I can't reproduce the problem without using Remix. Should this issue be reported on Remix instead of Vite?

Reproduction

(just follow the repro steps)

Steps to reproduce

bunx create-remix@latest
cd my-remix-app
bun add -d vite@6
bun --bun remix vite:dev

View it in your browser.
Notice there is a flash of unstyled content every time you refresh.
Each time, it will print this to the console:
Could not load /Users/me/my-remix-app/app/tailwind.css

System Info

System:
    OS: macOS 15.1.1
    CPU: (8) arm64 Apple M1
    Memory: 94.38 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 16.10.0 - ~/.nvm/versions/node/v16.10.0/bin/node
    Yarn: 1.22.21 - ~/.nvm/versions/node/v16.10.0/bin/yarn
    npm: 7.24.0 - ~/.nvm/versions/node/v16.10.0/bin/npm
    bun: 1.1.37 - ~/.bun/bin/bun
  npmPackages:
    vite: 6 => 6.0.1

Used Package Manager

bun

Logs

Could not load /Users/me/my-remix-app/app/tailwind.css

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

Can your ask Remix / react-router for Vite 6 support? There are a few breaking change which needs to be addressed by framework. As far as I can tell, they still have peer dev with Vite 5, so I would imagine you have peer dep warning if you try Vite 6.