404 error using revalidate and useFetcher with v3_lazyRouteDiscovery

[ataias]

Reproduction

Calling revalidator.revalidate() as well as having a fetcher active trigger a "Not Found" error that does not seem catchable nor recoverable, even if the endpoint actually exists. You can see that happening in https://github.com/ataias/remix-use-fetcher-with-resource-route . Both dev mode and the production build suffer from the same issue.

System Info

System:
  OS: macOS 15.1.1
  CPU: (10) arm64 Apple M1 Pro
  Memory: 253.61 MB / 16.00 GB
  Shell: 3.7.1 - /opt/homebrew/bin/fish
Binaries:
  Node: 22.11.0 - /opt/homebrew/opt/node@22/bin/node
  npm: 10.9.0 - /opt/homebrew/opt/node@22/bin/npm
  pnpm: 8.6.9 - /opt/homebrew/bin/pnpm
  bun: 1.1.34 - /opt/homebrew/bin/bun
Browsers:
  Chrome: 131.0.6778.86
  Safari: 18.1.1
npmPackages:
  @remix-run/dev: 2.15.0 => 2.15.0 
  @remix-run/node: 2.15.0 => 2.15.0 
  @remix-run/react: 2.15.0 => 2.15.0 
  @remix-run/serve: 2.15.0 => 2.15.0 
  vite: ^5.1.0 => 5.4.11

Used Package Manager

npm

Expected Behavior

Opening the home page in repo https://github.com/ataias/remix-use-fetcher-with-resource-route should not hit the ErrorBoundary

Actual Behavior

Opening the home page in repo https://github.com/ataias/remix-use-fetcher-with-resource-route hits the error boundary with error No route matches URL "/en-br/api/hello-world-1?fetcher-1". However, the route exists.

[danielmoraes]

I can confirm that I am also experiencing this issue.

[joshbuddy]

I'm having a more flaky and tougher to reproduce issue which is when I have v3_lazyRouteDiscovery enabled I eventually get a 404 error from client-side routing. But I haven't nailed down a cause for this issue. I was hoping to find some sort of debug mode for the router to see what's going on inside there, but so far have been unable to find this option.