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

Calculating dependencies ... done!
Dependency resolution took 1.64 s (backtrack: 0/20).

[ebuild  N     ] app-text/dos2unix-7.5.7::gentoo  USE="nls -debug -test -verify-sig" 977 KiB
[ebuild  N     ] dev-lang/ghc-9.2.8:0/9.2.8::gentoo  USE="gmp (-big-endian) -binary -doc -elfutils -ghcbootstrap -ghcmakebinary (-llvm) -numa -profile -test -unregisterised" 145134 KiB
[ebuild  N     ] app-admin/haskell-updater-1.5.0.0::gentoo  45 KiB
[ebuild  N     ] dev-haskell/cabal-3.6.3.0:0/3.6.3.0::gentoo  USE="-doc -hscolour -profile" 595 KiB
[ebuild  N     ] dev-haskell/cabal-doctest-1.0.9:0/1.0.9::gentoo  USE="-doc -hscolour -profile" 11 KiB

Total: 5 packages (5 new), Size of downloads: 146759 KiB

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

dev-lang/ghc:0

  (dev-lang/ghc-9.8.4-r1:0/9.8.4::gentoo, ebuild scheduled for merge) USE="gmp (-big-endian) -doc -elfutils -ghcbootstrap -ghcmakebinary -llvm -numa -profile -test -unregisterised -verify-sig" LLVM_SLOT="20 -17 -18 -19" conflicts with
    <dev-lang/ghc-9.3:= required by (dev-haskell/cabal-3.6.3.0:0/3.6.3.0::gentoo, ebuild scheduled for merge) USE="-doc -hscolour -profile"
    ^             ^^^