How to Fix gThumb Hanging on Startup

2018-10-29

After switching to Pop!_OS recently, I decided to use the gThumb photo browser to manage my photos.

It worked well for a while, and then one day it refused to start up properly. The application became unresponsive while starting up and displayed a "Getting the folder content..." message. Looking at the process in Gnome's System Monitor application, I could see gThumb using about 25% of the processor and writing to disk consistently.

I wondered if it was a problem with the particular directory, so I used dconf-editor to explore gThumb's settings and look for a way to change the startup directory. Eventually I found the "go-to-last-location" setting and turned it off with the "gsettings" command:

gsettings set org.gnome.gthumb.browser go-to-last-location false

This allowed gThumb to start up, but the problem still happened whenever I navigated to any directory that contained photos.

Wondering why gThumb was writing to disk, I remembered seeing some ".comments" directories within the individual photo directories. The gThumb application creates these directories within each photo directory with one XML file per image file. The XML files contain metadata for the image files such as comments and tags. I turned this off using the "gsettings" command again:

gsettings set org.gnome.gthumb.comments synchronize false

After this, gThumb started successfully!

I couldn't find any good documentation on the "synchronize" setting above, though, and I was curious to know whether gThumb would still save photo metadata inside the image files with this setting turned off. To test it, I first added a tag to one of my photos with gThumb. Then I used ImageMagick's "identify" command to verify that the tag was was still saved within the image:

identify -verbose someImageFile.jpg | grep -i "Keyword"