php7-imagick is missing a dependency in Alpine 3.7
Attempting to do anything with the imagick PHP extension causes an exception to be thrown.
Comparing the package from 3.6 to the package from 3.7, 3.7 depends on imagemagick-libs where 3.6 depends on imagemagick.
Adding the imagemagick package into my Alpine installation fixes my issues with the imagick PHP extension.
The php7-imagick package for Alpine 3.7 should depend on the imagemagick package.
(from redmine: issue id 8263, created on 2017-12-08, closed on 2018-08-10)