Comment 13 for bug 1838008

So you're unpacking gtk-common-themes, adding something (xxx ?) to the icon theme, and repacking it. Can you explain why you're doing that?

The correct way would be to submit a PR against https://github.com/ubuntu/gtk-common-themes, which would address the problem you're encountering for everyone, and would ensure your modifications aren't discarded the next time the snap is updated.