Linux Mint 17.2 に RMagick を入れる

ImageMagick を Ruby で使おうと、Bundler で RMagick という Gem を入れようと思ったのだが、エラーが出た。ImageMagick は入っているのだが。

OS は Linux Mint 17.2。次のエラー。

Installing rmagick 2.15.4 with native extensions

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /home/***i/.rbenv/versions/2.2.3/bin/ruby -r ./siteconf20160430-4264-2kinrp.rb extconf.rb
checking for gcc... yes
checking for Magick-config... no
checking for pkg-config... yes
Package MagickCore was not found in the pkg-config search path.
Perhaps you should add the directory containing `MagickCore.pc'
to the PKG_CONFIG_PATH environment variable
No package 'MagickCore' found
checking for outdated ImageMagick version (<= 6.4.9)... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/home/***/.rbenv/versions/2.2.3/bin/$(RUBY_BASE_NAME)

extconf failed, exit code 1

Gem files will remain installed in /home/***/Documents/Ruby/vendor/bundle/ruby/2.2.0/gems/rmagick-2.15.4 for inspection.
Results logged to /home/***/Documents/Ruby/vendor/bundle/ruby/2.2.0/extensions/x86_64-linux/2.2.0-static/rmagick-2.15.4/gem_make.out

色いろぐぐってみたところ、開発用のライブラリが入っていないらしい。

ここを参考に

$ sudo apt-get install imagemagick libmagickcore-dev libmagickwand-dev

を実行。あとは bundle install で OK でした。