Install Rmagick 3.1 on Archlinux

* get imagemagick6, libimagemagick6
* export PKG_CONFIG_PATH=/usr/lib/imagemagick6/pkgconfig

So you’re doing ruby development in 2019, eh? Good for you! Despite the rumors, Ruby on Rails is still a great way to get a project up and running. I managed to get the core of up and running in a week. One of my clients is also still running Ruby and I need to upgrade them from an old 2.3.3 version to 2.6.2. With that I decided to update a bunch of old gems too. One of those is Rmagick.

I didn’t have any problems with it on my Debian install. But on Arch I kept getting an error.

checking for brew... no
checking for gcc... yes
checking for pkg-config... yes

ERROR: Can't install RMagick 3.1.0. Can't find ImageMagick with pkg-config

*** extconf.rb failed ***

Googling solutions always brought me back to a missing libmagickwand-dev for Debian/Ubuntu. Those packages don’t exist on Arch so I was at a loss. Fortunately a while back I remember having a similar problem on Mac OS and recall the solution was to set the PKG_CONFIG path. Sure enough, that solves the problem here too:

export PKG_CONFIG_PATH=/usr/lib/imagemagick6/pkgconfig

After that installing the rmagick gem directly or via bundler would work just fine.