pythonPackages.keepkey: fix impossible constraint

pkgs/development/python-modules/keepkey/default.nix

@@ -0,0 +1,30 @@
+{ stdenv, fetchPypi, buildPythonPackage, ecdsa
+, mnemonic, protobuf3_0, hidapi }:
+
+buildPythonPackage rec {
+  name = "${pname}-${version}";
+  pname = "keepkey";
+  version = "0.7.3";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "14d2r8dlx997ypgma2k8by90acw7i3l7hfq4gar9lcka0lqfj714";
+  };
+
+  propagatedBuildInputs = [ protobuf3_0 hidapi ];
+
+  buildInputs = [ ecdsa mnemonic ];
+
+  # There are no actual tests: "ImportError: No module named tests"
+  doCheck = false;
+
+  # Remove impossible dependency constraint
+  postPatch = "sed -i -e 's|hidapi==|hidapi>=|' setup.py";
+
+  meta = with stdenv.lib; {
+    description = "KeepKey Python client";
+    homepage = https://github.com/keepkey/python-keepkey;
+    license = licenses.gpl3;
+    maintainers = with maintainers; [ np ];
+  };
+}