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

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] dev-lang/ocaml-5.5.1:0/5.5.1::gentoo  USE="ocamlopt -emacs -flambda -latex -test -xemacs" 6457 KiB
[ebuild  N     ] dev-ml/dune-3.23.1:0/3.23.1::gentoo  USE="-emacs -test" 3624 KiB
[ebuild  N     ] dev-ml/findlib-1.9.8-r1:0/1::gentoo  USE="ocamlopt -doc -tk" 269 KiB
[ebuild  N     ] dev-ml/ocamlbuild-0.16.1:0/0.16.1::gentoo  USE="ocamlopt" 198 KiB
[ebuild  N     ] dev-ml/cppo-1.8.0:0/1.8.0::gentoo  USE="ocamlopt" 43 KiB
[ebuild  N     ] dev-ml/merlin-extend-0.6.1:0/0.6.1::gentoo  USE="ocamlopt" 8 KiB

Total: 6 packages (6 new), Size of downloads: 10597 KiB