We recently upgraded a Rails project from Rails 5 to 6. It was pretty smooth in general, but I noticed in development (with Docker) that views weren't updating with changes - as if they were being cached.
The culprit turned out to be this segment of
# Use an evented file watcher to asynchronously detect changes in source code, # routes, locales, etc. This feature depends on the listen gem. config.file_watcher = ActiveSupport::EventedFileUpdateChecker
ActiveSupport::EventedFileUpdateChecker dislikes either Docker volumes or Windows - I'm leaning towards the latter and it being a dependency issue relating to FS notifications.
If you're hitting this issue: just comment out the
config.file_watcher line and you'll be back on track.