I think this is also affecting imagemagick and vipsthumbnail. I do have all the libheif-plugin-* packages installed. I'm running testing and have libheif 1.16.2-2 installed.
$ convert -debug IMG_3192.HEIC test.jpg convert-im6.q16: unrecognized event type `IMG_3192.HEIC' @ error/convert.c/ConvertImageCommand/1193. $ vipsthumbnail --size=256x256 ./IMG_3192.HEIC (vipsthumbnail:396906): VIPS-WARNING **: 11:43:28.704: error in tile 0 x 0 (vipsthumbnail:396906): VIPS-WARNING **: 11:43:28.704: error in tile 0 x 0 (vipsthumbnail:396906): VIPS-WARNING **: 11:43:28.704: error in tile 0 x 10 (vipsthumbnail:396906): VIPS-WARNING **: 11:43:28.705: error in tile 0 x 20 (vipsthumbnail:396906): VIPS-WARNING **: 11:43:28.705: error in tile 0 x 0 vipsthumbnail: unable to thumbnail ./IMG_3192.HEIC ./IMG_3192.HEIC: bad seek to 1446629 heif: Unsupported feature: Unsupported codec (4.3000)
