Add global exception handler to nitropy command

This patch introduces a wrapper around the nitropy command,
pynitrokey.cli.main, that catches unhandled exceptions and uses
local_critical to display them to the user.  For more consistency, we
also move the CliException handling to that wrapper.

Note that this changes the main entry point from pynitrokey.cli.nitropy
to pynitrokey.cli.main, so developers have to run `make update-venv` to
apply this change.

Fixes #193

nitropy.py

@@ -10,8 +10,6 @@
 #    #print (os.environ["PATH"])
 
 
-from pynitrokey.cli import nitropy
-
-nitropy()
-
+from pynitrokey.cli import main
 
+main()

pynitrokey/cli/__init__.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright 2019 SoloKeys Developers
+# Copyright 2022 Nitrokey Developers
 #
 # Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
 # http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
@@ -16,16 +17,20 @@
 
 import pynitrokey
 import pynitrokey.fido2.operations
+from pynitrokey.cli.exceptions import CliException
 from pynitrokey.cli.fido2 import fido2
 from pynitrokey.cli.nethsm import nethsm
 from pynitrokey.cli.nk3 import nk3
 from pynitrokey.cli.pro import pro
 from pynitrokey.cli.start import start
 from pynitrokey.cli.storage import storage
 from pynitrokey.confconsts import LOG_FN, LOG_FORMAT
+from pynitrokey.helpers import local_critical
 
 # from . import _patches  # noqa  (since otherwise "unused")
 
+logger = logging.getLogger(__name__)
+
 
 def check_root():
     if (os.name == "posix") and os.environ.get("ALLOW_ROOT") is None:
@@ -93,3 +98,13 @@ def ls():
 
 nitropy.add_command(list)
 nitropy.add_command(ls)
+
+
+def main() -> None:
+    try:
+        nitropy()
+    except CliException as e:
+        e.show()
+    except Exception as e:
+        logger.warning("An unhandled exception occured", exc_info=True)
+        local_critical("An unhandled exception occured", e)

pynitrokey/cli/exceptions.py

@@ -7,12 +7,10 @@
 # http://opensource.org/licenses/MIT>, at your option. This file may not be
 # copied, modified, or distributed except according to those terms.
 
-import click
-
 from pynitrokey.helpers import local_critical
 
 
-class CliException(click.ClickException):
+class CliException(Exception):
     def __init__(
         self, *messages, support_hint: bool = True, ret_code: int = 1, **kwargs
     ):

pyproject.toml

@@ -53,7 +53,7 @@ dev = [
 Source = "https://github.com/Nitrokey/pynitrokey"
 
 [project.scripts]
-nitropy = "pynitrokey.cli:nitropy"
+nitropy = "pynitrokey.cli:main"
 
 [tool.isort]
 profile = "black"