I have a python app that uses GExiv2 to add gps info to the images.

It modifies the image with teself.exif.set_gps_info(self.longitude, self.latitude, self.altitude)

self.exif[IPTC + 'City'] = self.names[0] or '' self.exif[IPTC + 'ProvinceState'] = self.names[1] or '' self.exif[IPTC + 'CountryName'] = self.names[2] or '' self.exif['Iptc.Envelope.CharacterSet'] = '\x1b%G' 

then it saves the file.

When trying to write a CR3 raw image I get the error "Setting Image comment in BMFF images is not supported".

However, the image hasn't any comment changed.

I'd expect a "Setting metadata in BMFF images is not supported" error message.