Why isn't calibre starting below?
nicholas@mordor:~$
nicholas@mordor:~$ sudo apt install calibre
Reading package lists... Done
Building dependency tree
Reading state information... Done
calibre is already the newest version (4.99.4+dfsg+really4.12.0-1build1).
The following packages were automatically installed and are no longer required:
linux-headers-5.4.0-51 linux-headers-5.4.0-51-generic linux-image-5.4.0-51-generic linux-modules-5.4.0-51-generic
linux-modules-extra-5.4.0-51-generic
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 232 not upgraded.
nicholas@mordor:~$
nicholas@mordor:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04 LTS
Release: 20.04
Codename: focal
nicholas@mordor:~$
nicholas@mordor:~$ calibre
Traceback (most recent call last):
File "/usr/bin/calibre", line 20, in <module>
sys.exit(calibre())
File "/usr/lib/calibre/calibre/gui_launch.py", line 73, in calibre
main(args)
File "/usr/lib/calibre/calibre/gui2/main.py", line 543, in main
listener = create_listener()
File "/usr/lib/calibre/calibre/gui2/main.py", line 514, in create_listener
return Listener(address=gui_socket_address())
File "/usr/lib/calibre/calibre/utils/ipc/server.py", line 110, in __init__
self._listener._unlink.cancel()
AttributeError: 'NoneType' object has no attribute 'cancel'
nicholas@mordor:~$
It's always run fine in the past, although I don't recall running it from this machine on which Ubuntu was recently installed.