impossible to install ghc-mod for ghc 8.6 about ghc-mod

[ubourdon]

new error when try cabal install

Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] trying: ghc-mod-5.9.0.0 (user goal)
[__1] next goal: base (dependency of ghc-mod)
[__1] rejecting: base-4.12.0.0/installed-4.1... (conflict: ghc-mod =>
base<4.12 && >=4.6.0.1)
[__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, ghc-mod)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: ghc-mod, base
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.

[DanielG]

Please see the readme, https://github.com/DanielG/ghc-mod#legacy

ghc-mod is no longer maintained.