02-27-2019, 04:55 PM
Asking about your installation did cross my mind but only after after posting 
Which linux distro?
The packages are all debian based, although I can get gmic_gimp_qt running in a PClinuxOS desktop which is rpm based
Sometimes you might be missing some QT5 packages - I have seen that one before. Run Gimp from a terminal gimp --verbose and look for errors.
Are you using a flatpack (or snap)? These are sandboxed and have no QT support - gmic_gimp_qt will not work.
One work-around albeit a cumbersome one, is using a Gimp 2.10 appimage that already contains gmic.
Frequent releases here: https://github.com/aferrero2707/gimp-appimage/releases/ I would try near the bottom of the list GIMP_AppImage-release-2.10.8-withplugins-x86_64.AppImage
Which linux distro?
The packages are all debian based, although I can get gmic_gimp_qt running in a PClinuxOS desktop which is rpm based
Sometimes you might be missing some QT5 packages - I have seen that one before. Run Gimp from a terminal gimp --verbose and look for errors.
Are you using a flatpack (or snap)? These are sandboxed and have no QT support - gmic_gimp_qt will not work.
One work-around albeit a cumbersome one, is using a Gimp 2.10 appimage that already contains gmic.
Frequent releases here: https://github.com/aferrero2707/gimp-appimage/releases/ I would try near the bottom of the list GIMP_AppImage-release-2.10.8-withplugins-x86_64.AppImage