flatpak: cannot add flathub repo on kubuntu 20.04 LTS: TLS support is not available

error: Can't load uri https://flathub.org/repo/flathub.flatpakrepo: TLS support is not available
 

Fix: need to set env. var:

 GIO_MODULE_DIR=/usr/lib/x86_64-linux-gnu/gio/modules/ flatpak -v remote-add --if-not-exists flathub
https://flathub.org/repo/flathub.flatpakrepo

XMP metadata manipulation

Add a new tag into existing subject tags in the .xmp sidecar:

exiv2 -M 'set Xmp.digiKam.TagsList my-new-tag'  mo xxx.JPG.xmp

exiv2 -M 'set Xmp.dc.subject my-new-tag'  mo xxx.JPG.xmp

 

Print specific tag:

exiv2 -g TagsList pr xxx.JPG.xmp