OK, let&#x27;s look at a practical example, something that frustrates me about many current web-related tools.<p>Tools like Sass and Watchify can monitor for file changes and automatically regenerate SCSS or Browserify outputs when known source files are modified. They also employ caching techniques to make that regeneration efficient, instead of rebuilding everything each time. This functionality is very helpful, and it is available with a simple shell command that works on any major platform.<p>However, at the moment such tools typically don&#x27;t notice when new source files are added and automatically start tracking them as well; this generally remains true even if the new file is imported by an existing known file. Similarly, such tools may break if a file that was being watched gets deleted.<p>In practice, this means you get automatic and efficient rebuilds as long as you are only changing known files, but you probably have to restart a watch process manually if you add or delete files. Fixing this would be high on my wish list for a modern web build tool, given what we already have.<p>How would you set Make up to solve this problem?