portage-ng / portage / sci-mathematics / ginac / 1.8.10
emerge -vp

These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] sci-libs/cln-1.3.7:1::gentoo  USE="-doc -examples" 1306 KiB
[ebuild  N     ] sci-mathematics/ginac-1.8.10::gentoo  USE="-doc -examples" 1483 KiB

Total: 2 packages (2 new), Size of downloads: 2789 KiB

Wall time
1.988 s vs. 0.012 s for portage-ng