I discovered that when a plugin is enabled, ghc will rebuild all modules even if only the top level module changed. I created a minimal example to reproduce this issue, see the [repo](https://github.com/coot/ghc-plugin-example). If I compile both modules: `A` and `B`, then I modify the top level one (`B`) and then recompiles again what GHC will do depends whether the plugin is enabled or not. In the first case it only recompiles the modified module, in the other case it will recompile both modules. I checked that for the `defaultPlugin` with `pluginRecompile` set to either of the two: `purePlugin` and `flagRecompile`. This might be a regression since the tickets #7414 and #12567 are both closed.