In KMail, I go to {Settings > Manage Sieve Scripts ...}. In the dialogue that opens, one of my servers/accounts is listed with a spinning circle and no sieve scripts. Waiting for several minutes shows no change in this situation. Right clicking on that account name and selecting {Cancel} has no effect, either. User journal (journalctl --user) shows no reaction to the "Cancel" action either, except the regular XCB errors. Please advise in how to debug this further.
P.S. Importing the Akonadi settings to Sieve Editor works: I can select and edit the script there without running into any issues of "spinning circles" or other forms of non-reaction.
Git commit bb78894acfa86d09b8274c193bfe23a5a02e5749 by Laurent Montel. Committed on 26/12/2017 at 06:59. Pushed by mlaurent into branch 'Applications/17.12'. Fix Bug 381714 - Cancelling sieve management operation has no effect FIXED-IN: 5.7.1 M +1 -1 src/ksieveui/widgets/managesievewidget.cpp https://commits.kde.org/libksieve/bb78894acfa86d09b8274c193bfe23a5a02e5749