@TilmanV this seems to be a upstream compile bug as this file (MagickCore.h) is present on arch system when the dep imagemagick is installed and the PKGFILE requires it to be.
You can follow http://dcpomatic.com/mantis/view.php?id=1150 in the dcpomatic bug tracker to learn what "upstream" (aka Carl) will have to say about this.
Pinned Comments
markusk commented on 2018-03-26 12:59 (UTC)
dcpomatic-git and it's depend "lib" packages where switched back to "bleeding edge" master branch! Use at own risk!
For production use better switch back to stable package at https://aur.archlinux.org/packages/dcpomatic/
Remember to deinstall all the "dcpomatic libs" when you switch from git to none git versions of my packages.