Simple fix for this one, kill the task directly by it’s PID. Using ps , grep and sed, to select correct process.
When executing this in live production, take especial care.
# xe task-list uuid ( RO) : 7cb8b30b-563c-db9e-7682-e25aac2b2f07 name-label ( RO): SR.scan name-description ( RO): status ( RO): pending progress ( RO): 0.000 [root@21-16-246-494694 ~]# date Thu Nov 10 11:41:45 UTC 2016 [root@xenhost ~]# kill -TERM $(ps fauxww | grep "[t]ap-ctl close" | sed -e "s/.*-p //" | awk '{print $1}')