Hopefully this hasn't already been listed, but here goes... I think it would be cool to have an option to emerge to make it run through the currently-installed packages checking if changes in the USE flags would affect that package, and if so re-emerge it. That way if you installed vim, then added "gnome" to your USE flags, emerge would rebuild the vim package so that you now had gvim. I know "emerge -e world" will do this but isn't that kind of like swatting a fly with a bus? ;) This could also be extended to notice changes to CFLAGS / CXXFLAGS, but that doesn't seem very useful to me since it seems that would end up doing 99% of an "emerge -e world" anyway... so if that were done it would probably need to be a separate flag from the one to notice USE changes...
Created attachment 2344 [details] Python script to perform the suggested enhancement
*** Bug 33766 has been marked as a duplicate of this bug. ***
--newuse in 2.0.51
Bug has been fixed and released in stable portages on or before 2.0.51-r2