portage-ng / portage / dev-haskell / stm / 2.5.0.1-r1
pmerge --pretend --verbose
!!! resolution failed
!!! request ( ( ('repo.livefs',) EqualityMatch: =False || ( ('category',) == virtual && ('package_is_real',) EqualityMatch: =False ) ) && =dev-haskell/stm-2.5.0.1-r1 ), mode none
!!! trying dev-haskell/stm-2.5.0.1-r1
!!!   request <dev-lang/ghc-9.1, mode depend
!!!   trying dev-lang/ghc-9.0.2-r4
!!!     failed due to failed inserting: [<PackageWrapper pkg=<<class 'pkgcore.ebuild.ebuild_src.package'> cpv='dev-lang/ghc-9.8.4-r1' @0x10ed210d0> wrapped='use' @0x10eee53d0>]
!!!   removing choices involving <dev-lang/ghc-9.1

Failures encountered:
!!! failed '( ( ('repo.livefs',) EqualityMatch: =False || ( ('category',) == virtual && ('package_is_real',) EqualityMatch: =False ) ) && =dev-haskell/stm-2.5.0.1-r1 )'
potentials:
repo gentoo: [ ebuild src: dev-haskell/stm-2.5.0.1-r1 ]

Wall time
0.443 s vs. 0.066 s for portage-ng