pandoc: manpages missing

[schmittlauch]

Issue description

While in other distributions pandoc does have a man page, the nixpkgs one doesn't seem to be available. I could find it neither in the pandoc nor the pandoc-data store directories. The expression also does not provide a separate man output directory.

potential fix

If I knew the supposed output path for man pages, I'd try to set the cabal configure --mandir=DIR flag accordingly.

Steps to reproduce

nix-shell -p pandoc --command "man pandoc"                                                                                                                                    
No manual entry for pandoc

Technical details

• system: "x86_64-linux"
• host os: Linux 4.14.79, NixOS, 18.09.1228.a4c4cbb613c (Jellyfish)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.1.3
• channels(root): "nixos-18.09.1228.a4c4cbb613c, nixos-unstable-19.03pre158246.6141939d6e0"
• channels(user): "home-manager-18.09"
• nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos

[Mic92]

Currently it is in data:

nix-shell -p haskellPackages.pandoc.data --run 'find $buildInputs | grep man1'
/nix/store/aw0rg6zwq8g476899baxf6n4i2inwdqp-pandoc-2.2.1-data/share/ghc-8.4.4/man/man1
/nix/store/aw0rg6zwq8g476899baxf6n4i2inwdqp-pandoc-2.2.1-data/share/ghc-8.4.4/man/man1/pandoc.1

It could be moved to the man output instead.

[cyounkins]

I think this is what is needed but I am having trouble with hackage2nix (see NixOS/cabal2nix#391)

diff --git a/pkgs/development/haskell-modules/configuration-common.nix b/pkgs/development/haskell-modules/configuration-common.nix
index 5f56dc3a9b6..4941c403e6c 100644
--- a/pkgs/development/haskell-modules/configuration-common.nix
+++ b/pkgs/development/haskell-modules/configuration-common.nix
@@ -1185,4 +1185,6 @@ self: super: {
   # });
   libnix = dontCheck super.libnix;

+  pandoc = appendConfigureFlag super.pandoc "--mandir=$out/share/man/man1";
+
 } // import ./configuration-tensorflow.nix {inherit pkgs haskellLib;} self super