pythonPackages.cmd2: keep 0.8 version

...which is the last one with python2 support until ~ august 2018

pkgs/development/python-modules/cmd2/old.nix

@@ -0,0 +1,49 @@
+{ stdenv, fetchPypi, buildPythonPackage, pythonOlder
+, pyperclip, six, pyparsing, vim
+, contextlib2 ? null, subprocess32 ? null
+, pytest, mock, which, fetchFromGitHub, glibcLocales
+}:
+buildPythonPackage rec {
+  pname = "cmd2";
+  version = "0.8.0";
+
+  src = fetchFromGitHub {
+    owner = "python-cmd2";
+    repo = "cmd2";
+    rev = version;
+    sha256 = "0nw2b7n7zg51bc3glxw0l9fn91mwjnjshklhmxhyvjbsg7khf64z";
+  };
+
+  LC_ALL="en_US.UTF-8";
+
+  postPatch = stdenv.lib.optional stdenv.isDarwin ''
+    # Fake the impure dependencies pbpaste and pbcopy
+    mkdir bin
+    echo '#/bin/sh' > bin/pbpaste
+    echo '#/bin/sh' > bin/pbcopy
+    chmod +x bin/{pbcopy,pbpaste}
+    export PATH=$(realpath bin):$PATH
+  '';
+
+  checkInputs= [ pytest mock which vim glibcLocales ];
+  checkPhase = ''
+    # test_path_completion_user_expansion might be fixed in the next release
+    py.test -k 'not test_path_completion_user_expansion'
+  '';
+  doCheck = !stdenv.isDarwin;
+
+  propagatedBuildInputs = [
+    pyperclip
+    six
+    pyparsing
+  ]
+  ++ stdenv.lib.optional (pythonOlder "3.5") contextlib2
+  ++ stdenv.lib.optional (pythonOlder "3.0") subprocess32
+  ;
+
+  meta = with stdenv.lib; {
+    description = "Enhancements for standard library's cmd module";
+    homepage = https://github.com/python-cmd2/cmd2;
+    maintainers = with maintainers; [ teto ];
+  };
+}

pkgs/top-level/python-packages.nix

@@ -9142,7 +9142,9 @@ in {
    cachetools_1 = callPackage ../development/python-modules/cachetools/1.nix {};
    cachetools = callPackage ../development/python-modules/cachetools {};
 
-  cmd2 = callPackage ../development/python-modules/cmd2 {};
+  cmd2_8 = callPackage ../development/python-modules/cmd2/old.nix {};
+  cmd2_9 = callPackage ../development/python-modules/cmd2 {};
+  cmd2 = if isPy27 then self.cmd2_8 else self.cmd2_9;
 
  warlock = buildPythonPackage rec {
    name = "warlock-${version}";