When I started the local server with rails s, I got the error No route matches [GET] "/ _next / webpack-hmr" every 20 seconds.
It was working normally until a day ago, so when I googled while thinking that it was strange, such an issue was on GitHub. ActionController::RoutingError (No route matches [GET] "/_next/webpack-hmr") every 20secs
The cause seems to be the Chrome tab of the Next.js app that I was working on separately.
The solution is just to close the Chrome tab in the Next.js app.
Without this issue, it would have taken a lot of time like this person. .. ..
So it can be solved in seconds, but since it is a seemingly mysterious problem, I posted it as a Japanese source for the time being.
I hope you find it useful.