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

Calculating dependencies ... done!
Dependency resolution took 1.54 s (backtrack: 0/20).

[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/dune-3.23.1:0/3.23.1::gentoo  USE="-emacs -test" 3624 KiB
[ebuild  N     ] dev-ml/sexplib0-0.16.0:0/0.16.0::gentoo  USE="ocamlopt" 22 KiB
[ebuild  N     ] dev-ml/result-1.5:0/1.5::gentoo  USE="ocamlopt" 3 KiB
[ebuild  N     ] dev-ml/csexp-1.5.2-r1:0/1.5.2::gentoo  USE="ocamlopt -test" 12 KiB
[ebuild  N     ] dev-ml/dune-configurator-3.21.1:0/3.21.1::gentoo  USE="ocamlopt" 3352 KiB
[ebuild  N     ] dev-ml/base-0.16.3-r1:0/0.16::gentoo  USE="ocamlopt" 433 KiB
[ebuild  N     ] dev-ml/typerep-0.16.0-r1:0/0.16::gentoo  USE="ocamlopt" 23 KiB

Total: 8 packages (8 new), Size of downloads: 12841 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 required by (dev-ml/typerep-0.16.0-r1:0/0.16::gentoo, ebuild scheduled for merge) USE="ocamlopt"
    ^               ^