home-manager: remove support for 19.09 releases

modules/home-manager.nix

@@ -7,11 +7,6 @@ with lib;
 let
   cfg = config.home-manager;
 
-  tryEval = builtins.tryEval (home-manager.path + "/modules/modules.nix");
-  assertionNixpkgs = types ? submoduleWith;
-  assertionHomeManager = tryEval.success && builtins.functionArgs (import tryEval.value) ? useNixpkgsModule;
-  assertion = assertionNixpkgs && assertionHomeManager;
-
   extendedLib = import (home-manager.path + "/modules/lib/stdlib-extended.nix") pkgs.lib;
 
   hmModule = types.submoduleWith {
@@ -54,10 +49,7 @@ in
       };
 
       config = mkOption {
-        type =
+        type = types.nullOr hmModule;
-          if assertion
-          then types.nullOr hmModule
-          else types.unspecified;
         default = null;
         description = "Home Manager configuration.";
       };
@@ -81,25 +73,7 @@ in
 
   ###### implementation
 
-  config = mkIf (cfg.config != null) (mkMerge [
+  config = mkIf (cfg.config != null) {
-
-    {
-      assertions = [
-        {
-          assertion = assertionNixpkgs;
-          message = "You are currently using release-19.09 branch or older of nixpkgs, you need "
-            + "to update to the release-20.03 channel or newer.";
-        }
-        {
-          assertion = assertionHomeManager;
-          message = "You are currently using release-19.09 branch or older of home-manager, you need "
-            + "to update to the release-20.03 channel or newer.";
-        }
-      ];
-    }
-
-    # hack to determine if cfg.config is a valid home-manager config
-    (mkIf (cfg.config ? home && cfg.config.home ? activationPackage) {
 
     inherit (cfg.config) assertions warnings;
 
@@ -130,7 +104,6 @@ in
       "profiles/per-user/${config.user.userName}".source =
         builtins.toPath "${config.user.home}/.nix-profile";
     };
-    })
 
-  ]);
+  };
 }