introduce UserFacingException

we should not raise generic Exception when wanting to communicate with
the user. it makes distinguishing programming errors and messages hard,
as the caller will necessarily need to catch all Exceptions then

electrum/plugin.py

@@ -32,7 +32,7 @@ from typing import NamedTuple, Any, Union, TYPE_CHECKING, Optional
 
 from .i18n import _
 from .util import (profiler, PrintError, DaemonThread, UserCancelled,
-                   ThreadJob, print_error)
+                   ThreadJob, print_error, UserFacingException)
 from . import bip32
 from . import plugins
 from .simple_config import SimpleConfig
@@ -500,6 +500,8 @@ class DeviceMgr(ThreadJob, PrintError):
                 continue
             try:
                 client = self.create_client(device, handler, plugin)
+            except UserFacingException:
+                raise
             except BaseException as e:
                 self.print_error(f'failed to create client for {plugin.name} at {device.path}: {repr(e)}')
                 continue