I have Gimp 2.10.22 running, which should have HEIC support according to the release notes from last October. So I would have expected that an iOS-created .heic file should open up. Unfortunately, I just get the generic "Unknown file type" error from Gimp when I try to open it there, or drag and drop into Gimp.
The release notes, as well as all the various third party announcements I've seen about the heic support fail to give an example of how to import/open the file.
So I'm stuck - how can I get Gimp to load a .heic image that was created by iOS?
Thanks to folks on the Gimp project (over at Gnome) this issue is due to my distro (Fedora 33) not supporting the heif format. So the version number is 2.10.22, but the heif/heic features are not actually present.
See the issue there.
Two simple workarounds: