portage-ng / portage / dev-ml / camlp4 / 5.3_p1
emerge -vp

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

Calculating dependencies ... done!
Dependency resolution took 0.99 s (backtrack: 0/20).

[ebuild  N     ] dev-lang/ocaml-5.3.0-r1:0/5.3.0::gentoo  USE="ocamlopt -emacs -flambda -latex -test -xemacs" 6094 KiB
[ebuild  N     ] dev-ml/findlib-1.9.8-r1:0/1::gentoo  USE="ocamlopt -doc -tk" 269 KiB
[ebuild  N     ] dev-ml/dune-3.23.1:0/3.23.1::gentoo  USE="-emacs -test" 3624 KiB
[ebuild  N     ] dev-ml/camlp-streams-5.0.1::gentoo  USE="ocamlopt" 17 KiB
[ebuild  N     ] dev-ml/ocamlbuild-0.16.1:0/0.16.1::gentoo  USE="ocamlopt" 198 KiB
[ebuild  N     ] dev-ml/camlp4-5.3_p1:0/5.3_p1::gentoo  USE="ocamlopt" 639 KiB

Total: 6 packages (6 new), Size of downloads: 10839 KiB

Wall time
1.959 s vs. 0.055 s for portage-ng