portage-ng --merge
>>> Emerging : portage://sci-mathematics/topcom-1.1.2:run?{[]}
These are the packages that would be merged, in order:
Calculating dependencies... done!
└─step 1─┤ download portage://sci-libs/cddlib-094n
│ └─ file ─┤ 1.32 Mb cddlib-0.94n.tar.gz
│ download portage://sci-mathematics/topcom-1.1.2
│ └─ file ─┤ 7.56 Mb TOPCOM-1_1_2.tgz
└─step 2─┤ install portage://sci-libs/cddlib-094n
│ └─ conf ─┤ USE = "-doc -examples -static-libs -tools"
└─step 3─┤ run portage://sci-libs/cddlib-094n
└─step 4─┤ install portage://sci-mathematics/topcom-1.1.2
│ └─ conf ─┤ USE = "-doc -examples"
└─step 5─┤ run portage://sci-mathematics/topcom-1.1.2
Total: 6 actions (2 downloads, 2 installs, 2 runs), grouped into 5 steps.
8.87 Mb to be downloaded.