An update to use the magick-core-7 is available there:
https://github.com/fccm2/mgk-gen2
If you still want to use the magick-core-6, the previous head is kept here:
https://github.com/fccm2/mgk-gen
The updated version was tested with the magick-core version 7.1.1-44, if you want to compile it, you need about 256M space left on device.