Stitched to stable branch for rust packages, added some emacs+python packages.

pkgs/pkgsets.nix

@@ -6,6 +6,7 @@ let
   cfg = config.machine;
   optPkgs = package: pkgstring: optionals (elem pkgstring cfg.pkgs) package;
   gitpkgs = import /nixpkgs {};
+  stablepkgs = import <nixos-stable> {};
 
   # Programms I'm likely to want on every machine and/or may execute as root
   base = with pkgs; [
@@ -85,7 +86,7 @@ let
     rainbow-delimiters # color parenthesis by indentation
     color-identifiers-mode
     /* Python */
-    company-jedi pylint melpaStablePackages.elpy
+    company-jedi pylint melpaStablePackages.elpy flycheck-mypy
     /* Git support */
     magit
     emms # multimedia support
@@ -119,6 +120,7 @@ let
     /* mail */ messages-are-flowing
     /* Nix */ nix-buffer nix-mode nixos-options company-nixos-options nix-sandbox
     paganini-theme
+    json-navigator
     spaceline # modeline beautification
     winum eyebrowse # window management
     auto-compile
@@ -203,6 +205,7 @@ let
     pylint
     pyopengl
     pyproj
+    pytest
     requests
     schedule
     scipy
@@ -234,7 +237,7 @@ let
 #    flaskbabel
   ] ++ optionals (elem "i3" cfg.desktop.wms) [ py3status pytz tzlocal ]);
 
-  rustpkgs = with pkgs; [
+  rustpkgs = with stablepkgs; [
     rustup
     carnix
     rustracer