これかいな？
`webpacker:clean` is deleting files when they are outputted more than 2 seconds apart · Issue #2441 · rails/webpacker · GitHub https://github.com/rails/webpacker/issues/2441
github.com`webpacker:clean` is deleting files when they are outputted more than 2 seconds apart · Issue #2441 · rails/webpackerIn 4.2.2, the webpacker:clean task is grouping all files that are not mentioned in manifest.json by their last modified time, down to a one-second resolution. This is meant to find very old version...