This sounds like it's really stuck.
If it's still running, please send a diagnostic report first. Open the QRecall app, choose
Help > Send Report.... The diagnostic report will sample all running QRecall components which will help identify exactly where it's at.
Afterwards, go ahead and kill the process and try the repair again. If the second try gets stuck too you might have a stale file locking semaphore on the file server.
There's a description of file locking / access problems in the help (Help > QRecall Help > Guide > Trouble Shooting > Problems > Can't Open Archive).
TL;DR: Restart your system AND your file server and try again.
Please let us know what worked (or didn't).