SUMMARY

After plugging in or out a USB card reader Digikam hangs, printing messages like this for at least a very long time:

digikam.general: slotSolidDeviceChanged: "/org/freedesktop/UDisks2/…"

STEPS TO REPRODUCE

1. Start Digikam
2. Plug in a USB stick

OBSERVED RESULT

After plugging in or out a USB card reader Digikam starts printing messages like this for every drive I have:

digikam.general: slotSolidDeviceChanged: "/org/freedesktop/UDisks2/…"

Interestingly, the first line, with "/org/freedesktop/UDisks2/block_devices/sdg1", is printed once, then a line with another drive is printed twice, then another four times, then eight, sixteen, and so on. Possibly this will end at some point, but I killed Digikam after about a minute of this.

EXPECTED RESULT

Digikam should not hang.

SOFTWARE/OS VERSIONS

KDE Frameworks 5.56.0
Qt 5.12.2 (built against 5.12.1)
The xcb windowing system