SUMMARY

Now I tried to scan for faces a large set of pictures, around 400. I basically selected them in the search view, right clicked, and selected "Scan for faces". After a few seconds, Digikam closed itself. I have been able to replicate that four times in a row.

This is what I see in the console (from the moment it starts scanning):

[New Thread 0x7fff70dea700 (LWP 8210)]
[New Thread 0x7fff5b7fe700 (LWP 8211)]
[New Thread 0x7fff5affd700 (LWP 8212)]
[New Thread 0x7fff5a7fc700 (LWP 8213)]
[New Thread 0x7fff59ffb700 (LWP 8214)]
[Thread 0x7fff5b7fe700 (LWP 8211) exited]
[Thread 0x7fff5affd700 (LWP 8212) exited]
[Thread 0x7fff5a7fc700 (LWP 8213) exited]
[Thread 0x7fff59ffb700 (LWP 8214) exited]
[New Thread 0x7fff59ffb700 (LWP 8236)]
[New Thread 0x7fff5a7fc700 (LWP 8239)]
[New Thread 0x7fff5affd700 (LWP 8240)]
[New Thread 0x7fff5b7fe700 (LWP 8241)]
[New Thread 0x7fff58d1a700 (LWP 8242)]
[Thread 0x7fff5a7fc700 (LWP 8239) exited]
[Thread 0x7fff5b7fe700 (LWP 8241) exited]
[Thread 0x7fff5affd700 (LWP 8240) exited]
[Thread 0x7fff58d1a700 (LWP 8242) exited]
Digikam::DImg::getUniqueHashV2: DImg::getUniqueHash called without originalFilePath property set!

Thread 43 "Thread (pooled)" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffb17fa700 (LWP 8194)]
0x00007ffff4122340 in QMapDataBase::rotateRight(QMapNodeBase*) ()
   from /tmp/.mount_digikatjz0Zx/usr/lib/libQt5Core.so.5
(gdb) bt
#0  0x00007ffff4122340 in QMapDataBase::rotateRight(QMapNodeBase*) () from /tmp/.mount_digikatjz0Zx/usr/lib/libQt5Core.so.5
#1  0x00007ffff41224c9 in QMapDataBase::rebalance(QMapNodeBase*) () from /tmp/.mount_digikatjz0Zx/usr/lib/libQt5Core.so.5
#2  0x00007ffff41229c4 in QMapDataBase::createNode(int, int, QMapNodeBase*, bool) () from /tmp/.mount_digikatjz0Zx/usr/lib/libQt5Core.so.5
#3  0x00007ffff71eaaf3 in Digikam::DImg::setAttribute(QString const&, QVariant const&) () from /tmp/.mount_digikatjz0Zx/usr/lib/libdigikamcore.so.7.0.0
#4  0x00007ffff708e12a in Digikam::DImgLoader::readMetadata(QString const&) () from /tmp/.mount_digikatjz0Zx/usr/lib/libdigikamcore.so.7.0.0
#5  0x00007fffc1165ff9 in ?? () from /tmp/.mount_digikatjz0Zx/usr/plugins/digikam/dimg/DImg_JPEG_Plugin.so
#6  0x00007ffff71e1fca in Digikam::DImg::load(QString const&, int, Digikam::DImgLoaderObserver*, Digikam::DRawDecoding const&) () from /tmp/.mount_digikatjz0Zx/usr/lib/libdigikamcore.so.7.0.0
#7  0x00007ffff72aef31 in ?? () from /tmp/.mount_digikatjz0Zx/usr/lib/libdigikamcore.so.7.0.0
#8  0x00007ffff72c4d7e in Digikam::LoadSaveThread::run() () from /tmp/.mount_digikatjz0Zx/usr/lib/libdigikamcore.so.7.0.0
#9  0x00007ffff72e9f9e in ?? () from /tmp/.mount_digikatjz0Zx/usr/lib/libdigikamcore.so.7.0.0
#10 0x00007ffff40e5d87 in ?? () from /tmp/.mount_digikatjz0Zx/usr/lib/libQt5Core.so.5
#11 0x00007ffff40e2335 in ?? () from /tmp/.mount_digikatjz0Zx/usr/lib/libQt5Core.so.5
#12 0x00007ffff32906db in start_thread (arg=0x7fffb17fa700) at pthread_create.c:463
#13 0x00007ffff2fb9a3f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb) 


 
I hope you find this information useful.



SOFTWARE/OS VERSIONS

Digikam 7.0.0 (stable) appimage on Ubuntu 18.04LTS