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haskellcabalcabal-install

Where does Cabal install a package globally on a Mac?

In macOS, if I execute

cabal install foo --global

where does cabal install the foo package?

Solution

  • There is no one place GHC stores global data—it depends on the configuration and that will vary by where you got GHC from (nixpkgs, Homebrew (brew), MacPorts, raw from GHCHQ, etc.). For your particular case, you can get information as described by DanielWagner:

    ghc-pkg describe unix --global

    And some simple shell scripting can extract the specific information you desire:

    ghc-pkg describe unix --global | egrep '^pkgroot' | cut -d' ' -f2

    Output:

    "/usr/local/Cellar/ghc/8.4.1/lib/ghc-8.4.1"

    Or:

    % nix-shell -p ghc
ghc-pkg describe unix --global | egrep '^pkgroot' | cut -d' ' -f2

    Output:

    "/nix/store/z0ypzmbhn6m0l2adzm8szcd72z7kwy04-ghc-8.0.2/lib/ghc-8.0.2"