portage-ng / portage / dev-ml / calendar / 2.04-r1
emerge -vp

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

Calculating dependencies ... done!
Dependency resolution took 1.62 s (backtrack: 4/20).

[ebuild  N     ] dev-lang/ocaml-4.14.2:0/4.14.2::gentoo  USE="ocamlopt -emacs -flambda -latex -xemacs" 5377 KiB
[ebuild  N     ] dev-ml/findlib-1.9.8::gentoo  USE="ocamlopt -doc -tk" 269 KiB
[ebuild  N     ] dev-ml/calendar-2.04-r1:0/2.04::gentoo  USE="ocamlopt -doc" 266 KiB

Total: 3 packages (3 new), Size of downloads: 5910 KiB

WARNING: One or more updates/rebuilds have been skipped due to a dependency conflict:

dev-lang/ocaml:0

  (dev-lang/ocaml-5.5.1:0/5.5.1::gentoo, ebuild scheduled for merge) USE="ocamlopt -emacs -flambda -latex -test -xemacs" conflicts with
    <dev-lang/ocaml-5:=[ocamlopt] required by (dev-ml/calendar-2.04-r1:0/2.04::gentoo, ebuild scheduled for merge) USE="ocamlopt -doc"
    ^               ^            


!!! The following update(s) have been skipped due to unsatisfied dependencies
!!! triggered by backtracking:

dev-ml/findlib:0

Wall time
2.732 s vs. 0.046 s for portage-ng