A partially downloaded tarball prevents emerge from emerging successfully and it stops and tells the user to delete the tarball file. The emerge should intelligently recognize this condition and delete the tarball itself and reattempt downloading w/o stopping or instructing the user to do this. This will allow administrators to start large emerges over the weekend and come back Monday and not see that emerge failed to build most of his packages.
We have added resume support to the latest _pre Portage, which should fix this problem.
