So i’ve problem when installing rmagick gem in macosx yosemite, although i’ve installed imagemagick on my system. The problem exists when bundler try to install rmagick gem and having trouble finding MagickWand.h for building native extension.

Can't install RMagick 2.13.2. Can't find MagickWand.h.
 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.

This problem can be solved by tell explicitly to rmagick where the path of imagemagick headers file with providing configuration options on gem installation, for example like,

gem install rmagick –with-opt-dir=your_path –with-opt-include=your_path

But this problem could be solve easily by installing pkgconfig first before installing imagemagick. So now you can install pkgconfig first and reinstall the imagemagick. If you’re using Homebrew

brew install pkgconfig
brew uninstall imagemagick && brew install imagemagick

Now after reinstallation, you can easilly install rmagick gem as usual gem install rmagick