portage-ng --merge
>>> Emerging : portage://games-engines/box2d-2.4.2-r1:run?{[]}
These are the packages that would be merged, in order:
Calculating dependencies... done!
└─step 1─┤ download portage://games-engines/box2d-2.4.2-r1
│ └─ file ─┤ 1.18 Mb box2d-2.4.2.tar.gz
└─step 2─┤ install portage://games-engines/box2d-2.4.2-r1
│ └─ conf ─┤ USE = "-doc -test"
└─step 3─┤ run portage://games-engines/box2d-2.4.2-r1
Total: 3 actions (1 download, 1 install, 1 run), grouped into 3 steps.
1.18 Mb to be downloaded.