Unsure if this has been suggested before, didn't check. Anyway: Most people that are new to Gentoo will not know that the files downloaded by the various ebuilds will remain in /usr/portage/distfiles until the end of time. There should be some form of semi-automatic cleaning in this directory, so that old files are removed to free up space. Not everyone has a 10Gb partition, and it can come as a nasty surprise to find that this dir takes up half your disk. This could be a user-defined threshold (make.conf?) so that before every emerge, the oldest file in the dir is removed until the dir takes up less than MAX_WHATSIT_USAGE Mb. There are some caveats here, namely that if you check too often then you might remove files neccessary for the current emerge. But that shouldn't be too difficult to avoid. Or a question/reminder after an emerge that the files are still there and can be removed. Anything is better than nothing.
*** This bug has been marked as a duplicate of 2567 ***
