ligthdm.md

This is all assuming you are on 17.03 as I haven't tested my changes against unstable. Leave a comment here if you have any questions.

• fork https://github.com/NixOS/nixpkgs on github

• clone it locally:

  $ git clone git@github.com:erlandsona/nixpkgs.git
  $ cd nixpkgs
  

• get channel information via git:

  $ git remote add channels git://github.com/NixOS/nixpkgs-channels.git
  $ git remote update channels
  

• set up new local branch based on 17.03:

  $ git checkout -b local-17.03 channels/nixos-17.03
  

• add a remote for my fork:

  $ git remote add pbogdan git@github.com:pbogdan/nixpkgs.git
  $ git remote update pbogdan
  

• pick the lightdm changes:

  $ git cherry-pick c48e9e386374ae4f3b90dbd64c2c934ce8475a36
  $ git cherry-pick 89e9f1473553114619738718173f82af19565063
  

  the c48e9e386374ae4f3b90dbd64c2c934ce8475a36 commit isn't really required but will save having to resolve a merge conflict manually as it's not in 17.03, see NixOS/nixpkgs#24135

• adjust /etc/nixos/configuration.nix with the new options:

  services.xserver = {
     ...
     displayManager = {
       lightdm = {
         enable = true;
           greeters = {
             gtk = {
               enable = true;
               cursorTheme = {
                 package = pkgs.gnome3.defaultIconTheme;
                 name = "Adwaita";
                 size = 32;
             };
           };
         };
      };
      ...
    };
  };
  

• rebuild the system using your own fork:

  $ sudo nixos-rebuild switch -I nixpkgs=/home/erlandsona/nixpkgs
  

  (adjust the path as needed)

You would need to use -I nixpkgs=/home/erlandsona/nixpkgs whenever your rebuild. If at some point you would want to use your own fork for your user with nix-env you can point to it with nix-env -i somepackage -f ~/nixpkgs/.

If you want to update and get the latest upstream changes from 17.03 you would run:

$ git remote update channels
$ git rebase channels/nixos-17.03