feat(third_party): Check in derivation for lieer

third_party/default.nix

@@ -68,6 +68,7 @@ let
       parallel
       pkgconfig
       protobuf
+      python3Packages
       remarshal
       rink
       ripgrep

third_party/lieer/default.nix

@@ -0,0 +1,27 @@
+# Lieer is a small tool to synchronise a Gmail account with a local
+# maildir.
+#
+# Lieer is packaged in nixpkgs, but as of 2019-12-23 it is an old
+# version using the previous branding (gmailieer).
+{ pkgs, ... }:
+
+with pkgs.third_party;
+
+python3Packages.buildPythonApplication rec {
+  name = "lieer-${version}";
+  version = "1.0";
+
+  src = fetchFromGitHub {
+    owner = "gauteh";
+    repo = "lieer";
+    rev = "v${version}";
+    sha256 = "1zzylv8xbcrh34bz0s29dawzcyx39lai8y8wk0bl4x75v1jfynvf";
+  };
+
+  propagatedBuildInputs = with python3Packages; [
+    notmuch
+    oauth2client
+    google_api_python_client
+    tqdm
+  ];
+}