PS D:\dev\ws\haskell> cabal update
Downloading the latest package list from hackage.haskell.org
To revert to previous state run:
cabal v2-update 'hackage.haskell.org,2020-04-07T05:55:26Z'
PS D:\dev\ws\haskell> cabal v2-install cabal-plan-0.6.2.0 --lib -w ghc-8.10.1
Resolving dependencies...
cabal.exe: Could not resolve dependencies:
[__0] trying: cabal-plan-0.6.2.0 (user goal)
[__1] next goal: base (dependency of cabal-plan)
[__1] rejecting: base-4.14.0.0/installed-4.14.0.0 (conflict: cabal-plan =>
[__1] rejecting: base-4.12.0.0, base-4.11.1.0, base-4.11.0.0, base-4.10.1.0,
base-4.10.0.0, base-4.9.1.0, base-4.9.0.0, base-4.8.2.0, base-4.8.1.0,
base-4.8.0.0, base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1,
base-4.6.0.0, base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0,
base-4.3.1.0, base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0,
base-4.1.0.0, base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from
non-upgradeable package requires installed instance)
[__1] fail (backjumping, conflict set: base, cabal-plan)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: base, cabal-plan
PS D:\dev\ws\haskell> cabal --version
cabal-install version 3.2.0.0
compiled using version 3.2.0.0 of the Cabal library