Try to bring the Nix configuration into good shape

Not currently working

autobahn.nix

+{ fetchFromGitHub, autobahn }:
+autobahn.overrideAttrs (old: rec {
+  pname = "autobahn";
+  version = "19.7.1";
+  src = fetchFromGitHub {
+    owner = "crossbario";
+    repo = "autobahn-python";
+    rev = "v${version}";
+    sha256 = "1gl2m18s77hlpiglh44plv3k6b965n66ylnxbzgvzcdl9jf3l3q3";
+  };
+})

cryptography.nix

+{ fetchFromGitHub, cryptography }:
+cryptography.overrideAttrs (old: rec {
+  pname = "cryptography";
+  version = "2.7";
+  src = fetchFromGitHub {
+    owner = "pyca";
+    repo = "cryptography";
+    rev = "2.7";
+    sha256 = "145byri5c3b8m6dbhwb6yxrv9jrr652l3z1w16mz205z8dz38qja";
+  };
+})

default.nix

 { pkgs ? import <nixpkgs> { } }:
 let
-  eliot = pkgs.pythonPackages.callPackage ./eliot.nix { };
-
-  # tahoe-lafs in nixpkgs is packaged as an application!  so we have to
-  # re-package it ourselves as a library.
-  tahoe-lafs = pkgs.pythonPackages.callPackage ./tahoe-lafs.nix {
-    inherit eliot;
-  };
-
+  newpkgs = import pkgs.path { overlays = [ import ./overlays.nix ]; };
 in
-  pkgs.pythonPackages.callPackage ./secure-access-token-authorizer.nix {
-    inherit tahoe-lafs;
-  }
+  pkgs.pythonPackages.callPackage ./secure-access-token-authorizer.nix { }

overlays.nix

+self: super: {
+  python = super.python.override {
+    packageOverrides = python-self: python-super: {
+      # new tahoe-lafs dependency
+      eliot = pkgs.pythonPackages.callPackage ./eliot.nix { };
+      # new autobahn requires a newer cryptography
+      cryptography = pkgs.pythonPackages.callPackage ./cryptography.nix { };
+      # new tahoe-lafs depends on a very recent autobahn for better
+      # websocket testing features.
+      autobahn = pkgs.pythonPackages.callPackage ./autobahn.nix { };
+
+      # tahoe-lafs in nixpkgs is packaged as an application!  so we have to
+      # re-package it ourselves as a library.
+      tahoe-lafs = pkgs.pythonPackages.callPackage ./tahoe-lafs.nix { };
+    };
+  };
+}

secure-access-token-authorizer.nix

-{ buildPythonPackage, sphinx, circleci-cli, pythonPackages, tahoe-lafs }:
+{ buildPythonPackage, sphinx, circleci-cli, pythonPackages }:
 buildPythonPackage rec {
   version = "0.0";
   name = "secure-access-token-authorizer-${version}";

tahoe-lafs.nix

-{ nettools, pythonPackages, buildPythonPackage, eliot }:
+{ fetchFromGitHub, nettools, pythonPackages, buildPythonPackage, eliot, autobahn }:
 buildPythonPackage rec {
   version = "1.14.0.dev";
   name = "tahoe-lafs-${version}";
-  src = ~/Work/python/tahoe-lafs;
+  src = fetchFromGitHub {
+    owner = "tahoe-lafs";
+    repo = "tahoe-lafs";
+    # HEAD of integration/storage-economics branch as of July 15th 2019.
+    rev = "48bd16a8d9109910122cc2e2c85eb4f378390135";
+    sha256 = "0i8k7zb4381vbblriciz1m33va0mxld6nrhpwvjqr9jk335b1a9q";
+  };
 
   postPatch = ''
     sed -i "src/allmydata/util/iputil.py" \
@@ -21,7 +27,7 @@ buildPythonPackage rec {
 
 
   propagatedBuildInputs = with pythonPackages; [
-    twisted foolscap nevow simplejson zfec pycryptopp darcsver
+    twisted autobahn foolscap nevow simplejson zfec pycryptopp darcsver
     setuptoolsTrial setuptoolsDarcs pycrypto pyasn1 zope_interface
     service-identity pyyaml magic-wormhole treq appdirs