Qubes Manager doesn’t catch all exceptions run_service() can raise

[DemiMarie]

How to file a helpful issue

Qubes OS release

R4.1

Brief summary

Qubes Manager doesn’t catch all exceptions run_service() can raise

Steps to reproduce

Apply the following patch to Qubes Manager, then try to use it to update a qube:

diff --git a/qubesmanager/qube_manager.py b/qubesmanager/qube_manager.py
index 62c68c59db56d71f5c8354bc12b3048236f1bdc1..ed72f148a8467721c12df3e261430af6bf263b5b 100644
--- a/qubesmanager/qube_manager.py
+++ b/qubesmanager/qube_manager.py
@@ -635,6 +635,7 @@ class UpdateVMThread(common_threads.QubesThread):
                     except exc.QubesDaemonAccessError:
                         # permission denied, let us hope for the best
                         pass
+                raise FileNotFoundError("test!")
                 self.vm.run_service("qubes.InstallUpdatesGUI",
                                     user="root", wait=False)
         except (ChildProcessError, subprocess.CalledProcessError,

Expected behavior

The exception should be caught, since self.vm.run_service() can raise FileNotFoundError if /usr/lib/qubes/qrexec-client is not found.

Actual behavior

The exception is not caught.