Subject: bug#31771: 26.1; [imagemagick] Writing image file with emacs hangs entire system

From: Joerg Kulbartz <[email-masked]>
Date: Mon, 23 Jul 2018 03:56:28 +0200

A workaround for the bug, at least for me, seems to disable OpenCL for
ImageMagick by setting the environment variable

MAGICK_OCL_DEVICE=OFF

(h/t https://bugs.archlinux.org/task/47864 )