kweathercore: init at v0.4

Why 0.4 when 0.5 is tagged? Because current kweather depends on 0.4 and
won't build with 0.5...

¯\_(ツ)_/¯

pkgs/development/libraries/kweathercore/default.nix

@@ -0,0 +1,35 @@
+{ mkDerivation
+, lib
+, fetchFromGitLab
+, extra-cmake-modules
+, ki18n
+, qtlocation
+}:
+
+mkDerivation rec {
+  pname = "kweathercore";
+  version = "0.4";
+
+  src = fetchFromGitLab {
+    domain = "invent.kde.org";
+    owner = "libraries";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "0mwmkr1xg0mcgbjgzp04chf55xyrgf0gndg3hs4c21bfjpy1gp3k";
+  };
+
+  buildInputs = [
+    ki18n
+    qtlocation
+  ];
+
+  nativeBuildInputs = [ extra-cmake-modules ];
+
+  meta = with lib; {
+    license = [ licenses.cc0 ];
+    maintainers = [ maintainers.samueldr ];
+    description = ''
+      Library to facilitate retrieval of weather information including forecasts and alerts
+    '';
+  };
+}

pkgs/top-level/qt5-packages.nix

@@ -108,6 +108,8 @@ in (kdeFrameworks // plasmaMobileGear // plasma5 // plasma5.thirdParty // kdeGea
 
   kquickimageedit = callPackage ../development/libraries/kquickimageedit { };
 
+  kweathercore = libsForQt5.callPackage ../development/libraries/kweathercore { };
+
   ldutils = callPackage ../development/libraries/ldutils { };
 
   libcommuni = callPackage ../development/libraries/libcommuni { };