Per https://bugzilla.redhat.com/show_bug.cgi?id=1840780#c2 this happens on python >= 3.8.3. As Focal ships 3.8.5 we get this bug. Juanjo linked and attached the upstream patch already, which is included in Calibre >= 4.15. Focal ships Calibre version 4.99.4 which I assume is some pre- release version of the Calibre 5 series which didn't yet include this fix. Calibre 5 is now available and presumably would also fix this issue.
** Summary changed: - Calibre crashes at startup with "/usr/bin/calibre, line 20" error + Calibre crashes at startup with AttributeError: 'NoneType' object has no attribute 'cancel' ** Bug watch added: Red Hat Bugzilla #1840780 https://bugzilla.redhat.com/show_bug.cgi?id=1840780 -- You received this bug notification because you are a member of Edubuntu Bugsquad, which is subscribed to calibre in Ubuntu. https://bugs.launchpad.net/bugs/1898904 Title: Calibre crashes at startup with AttributeError: 'NoneType' object has no attribute 'cancel' To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/calibre/+bug/1898904/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~edubuntu-bugs Post to : edubuntu-bugs@lists.launchpad.net Unsubscribe : https://launchpad.net/~edubuntu-bugs More help : https://help.launchpad.net/ListHelp
