Remove Nevow dependency from the Nix packaging

nix/nevow.nix

@@ -1,45 +0,0 @@
-{ stdenv, buildPythonPackage, fetchPypi, isPy3k, twisted }:
-
-buildPythonPackage rec {
-  pname = "Nevow";
-  version = "0.14.5";
-  name = "${pname}-${version}";
-  disabled = isPy3k;
-
-  src = fetchPypi {
-    inherit pname;
-    inherit version;
-    sha256 = "1wr3fai01h1bcp4qpia6indg4qmxvywwv3q1iibm669mln2vmdmg";
-  };
-
-  propagatedBuildInputs = [ twisted ];
-
-  checkInputs = [ twisted ];
-
-  checkPhase = ''
-    trial formless nevow
-  '';
-
-  meta = with stdenv.lib; {
-    description = "Nevow, a web application construction kit for Python";
-    longDescription = ''
-      Nevow - Pronounced as the French "nouveau", or "noo-voh", Nevow
-      is a web application construction kit written in Python.  It is
-      designed to allow the programmer to express as much of the view
-      logic as desired in Python, and includes a pure Python XML
-      expression syntax named stan to facilitate this.  However it
-      also provides rich support for designer-edited templates, using
-      a very small XML attribute language to provide bi-directional
-      template manipulation capability.
-
-      Nevow also includes formless, a declarative syntax for
-      specifying the types of method parameters and exposing these
-      methods to the web.  Forms can be rendered automatically, and
-      form posts will be validated and input coerced, rendering error
-      pages if appropriate.  Once a form post has validated
-      successfully, the method will be called with the coerced values.
-    '';
-    homepage = https://github.com/twisted/nevow;
-    license = licenses.mit;
-  };
-}

nix/overlays.nix

@@ -3,10 +3,7 @@ self: super: {
     packageOverrides = python-self: python-super: {
       # eliot is not part of nixpkgs at all at this time.
       eliot = python-self.callPackage ./eliot.nix { };
-      # The packaged version of Nevow is very slightly out of date but also
-      # conflicts with the packaged version of Twisted.  Supply our own
-      # slightly newer version.
-      nevow = python-super.callPackage ./nevow.nix { };
+
       # NixOS autobahn package has trollius as a dependency, although
       # it is optional. Trollius is unmaintained and fails on CI.
       autobahn = python-super.callPackage ./autobahn.nix { };

nix/tahoe-lafs.nix

@@ -1,6 +1,6 @@
 { fetchFromGitHub, lib
 , nettools, python
-, twisted, foolscap, nevow, zfec
+, twisted, foolscap, zfec
 , setuptools, setuptoolsTrial, pyasn1, zope_interface
 , service-identity, pyyaml, magic-wormhole, treq, appdirs
 , beautifulsoup4, eliot, autobahn, cryptography
@@ -46,7 +46,7 @@ python.pkgs.buildPythonPackage rec {
   ];
 
   propagatedBuildInputs = with python.pkgs; [
-    twisted foolscap nevow zfec appdirs
+    twisted foolscap zfec appdirs
     setuptoolsTrial pyasn1 zope_interface
     service-identity pyyaml magic-wormhole treq
     eliot autobahn cryptography setuptools