Replace xclip with xsel

The latter might support large copies:
kfish/xsel#14

home/x11/i3/default.nix

@@ -9,11 +9,11 @@ let
   guile = "${pkgs.guile}/bin/guile";
   zsh = "${pkgs.zsh}/bin/zsh";
   emacs = "${pkgs.emacs}/bin/emacs";
-  xclip = "${pkgs.xclip}/bin/xclip";
+  xsel = lib.getExe pkgs.xsel;
   rofi = "${pkgs.rofi}/bin/rofi";
   unipicker = "${pkgs.unipicker}/bin/unipicker";
   xclip-both = pkgs.writeShellScript "xclip-both" ''
-    ${xclip} -sel pri -f | ${xclip} -sel clip
+    ${xsel} -i -p | ${xsel} -i -b
   '';
   pgrep = "${pkgs.procps}/bin/pgrep";
 

modules/clipboard.nix

@@ -7,23 +7,23 @@ in
   options.clipboard = {
     default-selection = mkOption {
       type = types.listOf types.str;
-      default = [ "-selection" "clipboard" ];
+      default = [ "--clipboard" ];
       description = ''
         Argument to the copy/paste program for the default selection (e.g.
         CTRL-C/CTRL-V).
       '';
     };
     alternate-selection = mkOption {
       type = types.listOf types.str;
-      default = [ "-selection" "primary" ];
+      default = [ "--primary" ];
       description = ''
         Argument to the copy/paste program for the default selection (e.g.
         CTRL-C/CTRL-V).
       '';
     };
     copy-command = mkOption {
       type = types.listOf types.str;
-      default = [ "${pkgs.xclip}/bin/xclip" "-i" ];
+      default = [ (lib.getExe pkgs.xsel) "-i" ];
       description = ''
         Can be used to override the copy command for programs (e.g. tmux, vim).
         For example use win32yank https://github.com/equalsraf/win32yank/ under
@@ -32,7 +32,7 @@ in
     };
     paste-command = mkOption {
       type = types.listOf types.str;
-      default = [ "${pkgs.xclip}/bin/xclip" "-o" ];
+      default = [ (lib.getExe pkgs.xsel) "-o" ];
       description = ''
         Can be used to override the paste command for programs (e.g. vim). For
         example use win32yank https://github.com/equalsraf/win32yank/ under

packages/desktop-environment.nix

@@ -37,7 +37,7 @@
 
     libnotify
     xdotool
-    xclip
+    xsel
     xorg.xev
     xorg.xkbprint
     xorg.xkbutils