cvs: fix cross; clarify license

pkgs/applications/version-management/cvs/default.nix

@@ -28,14 +28,23 @@ stdenv.mkDerivation {
     done
   '';
 
-  buildInputs = [ nano ];
+  configureFlags = [
+    "--with-editor=${nano}/bin/nano"
+
+    # Required for cross-compilation.
+    "cvs_cv_func_printf_ptr=yes"
+  ];
+
+  makeFlags = [
+    "AR=${stdenv.cc.targetPrefix}ar"
+  ];
 
   doCheck = false; # fails 1 of 1 tests
 
   meta = with lib; {
     homepage = "http://cvs.nongnu.org";
     description = "Concurrent Versions System - a source control system";
-    license = licenses.gpl2; # library is GPLv2, main is GPLv1
+    license = licenses.gpl2Plus; # library is GPLv2, main is GPLv1
     platforms = platforms.all;
   };
 }