convert: data storage type is not supported when opening a gimp 2.10 xcf image

[riskboy]

Problem Summary/Steps to Reproduce

The following command failed when attempting to use convert on an xcf image, generated from gimp 2.10:

convert 20190527.xcf 20190527.jpg
convert: data storage type is not supported `20190527.xcf' @ error/xcf.c/ReadXCFImage/1191.
convert: no images defined `20190527.jpg' @ error/convert.c/ConvertImageCommand/3273.

Note that the test image can be accessed from the following URL:
https://www.saxbynet.com/images/imagema ... 190527.xcf

Note that I am able to successfully convert an xcf image from earlier version of gimp (2.8 series) and at least some simple images generated by gimp 2.10. Therefore, I surmise that perhaps the recent changes in the xcf file format may not all have been dealt with by ImageMagick.

System Information

convert -version
Version: ImageMagick 7.0.8-46 Q16 x86_64 2019-05-26 https://imagemagick.org
Copyright: © 1999-2019 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC HDRI OpenMP(4.5)
Delegates (built-in): bzlib fftw fontconfig freetype jng jpeg lcms lzma pangocairo png tiff x xml zlib

gimp -v
GNU Image Manipulation Program version 2.10.10
git-describe: GIMP_2_10_8-775-g596f855749
C compiler:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,objc,obj-c++,ada,go,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl --enable-libmpx --enable-offload-targets=nvptx-none --without-cuda-driver --enable-gnu-indirect-function --enable-cet --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 8.3.1 20190223 (Red Hat 8.3.1-2) (GCC)

using GEGL version 0.4.14 (compiled against version 0.4.14)
using GLib version 2.58.3 (compiled against version 2.58.3)
using GdkPixbuf version 2.38.1 (compiled against version 2.38.1)
using GTK+ version 2.24.32 (compiled against version 2.24.32)
using Pango version 1.42.3 (compiled against version 1.42.3)
using Fontconfig version 2.13.1 (compiled against version 2.13.1)
using Cairo version 1.16.0 (compiled against version 1.16.0)

uname -a
Linux sarah 5.0.16-200.fc29.x86_64 #1 SMP Tue May 14 18:27:35 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

[magick]

Not a bug. ImageMagick is behaving properly. It does not support high bit-depth images exported by Gimp 2.10 and alerts you when you try to read the image. Two solutions. One, save your image in the Gimp 2.8 compatible format or wait for a patch to the XCF reader in ImageMagick. We do not have an ETA on the patch. It may be quite some time before Gimp 2.10 features are supported.