Bug 472452

+++ This bug was initially created as a clone of Bug #460570 +++


SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***


STEPS TO REPRODUCE
1. Launch
2. People -> Settings -> [X] Work on all processor cores
3. Scan collection for faces
 
OBSERVED RESULT
Face detection hangs at 0% and digikam must be force killed.

EXPECTED RESULT
Face detection scan proceeds

WORKAROUND
Perform a small scan with "Work on all processor cores" unchecked
Perform a subsequent scan with "Work on all processor cores" checked
SOFTWARE/OS VERSIONS
Windows: Windows 11
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***
Selecting People module and performing a scan on selected directories/Albums on an external drive, process remains at 0% showing only some results in Unknown People tab.  External drive then switches its light off (meaning that there is no request for data from it) and process still remains at 0% on digikam.  At the same time the laptop remains relatively cool meaning that there is no high demanding process running actually on it (such as face detection).

Reproduced in two different by gen laptops (Lenovo X1 Carbon gen2 and gen3 respectivelly) with the same external drive used.

STEPS TO REPRODUCE
1. Workflow tab: Skip images already scanned
Detect faces
Search in tab: 5 Albums selected
Settings tab: Use YOLO v3 detection model (not selected/unchecked)
Work on all processor cores (selected/checked)
2. External drive connected to laptop with those 5 Albums selected from
3. Irelevant: Settings: Miscellaneous - System - Disable hardware acceleration OpenCL (checked or unchecked with restart makes no difference)
4. 

OBSERVED RESULT
Process is stuck with message on screen "Updating faces data base" 0%
No activity on external disk
Laptop remains relatively cool for such a cpu demanting process.
No results in People-Unknown (or other) tab except from few findings wich might even not be from those directories selected.

EXPECTED RESULT
In People-Unkown tab should expect results from all the directories in a discent amount of time with the bar and percentage moving from 0% to 100%.  From there and as the Detect faces was selectted for this bug report, one could tag enough faces so for the Recognise faces to take part afterwards as a second step/scan.

SOFTWARE/OS VERSIONS
Windows: Windows 10 Version 2009 (x86_64)
macOS: nan
Linux/KDE Plasma: nan
(available in About System)
KDE Plasma Version: nan
KDE Frameworks Version: nan
Qt Version: nan

ADDITIONAL INFORMATION