I get this error when installing Imagemagick@6 on my mac. This is stopping me from running the rails app on my local machine. I tried a bunch of options like changing the bash profile, adding things to config etc. I tried removing the gem and the rmv file and reinstalling again.
Here is what I get every time.
Building native extensions with: '--with-opt-lib /usr/local/opt/imagemagick@6/lib --with-opt-include /usr/local/opt/imagemagick@6/include'
This could take a while...
ERROR: Error installing rmagick:
ERROR: Failed to build gem native extension.
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb --with-opt-lib /usr/local/opt/imagemagick@6/lib --with-opt-include /usr/local/opt/imagemagick@6/include
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:1674:in `dir_config': undefined method `split' for true:TrueClass (NoMethodError)
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:2378:in `init_mkmf'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:2415:in `<module:MakeMakefile>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:47:in `<top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from extconf.rb:4:in `<main>'
Gem files will remain installed in /Users/neves/.rvm/gems/ruby-2.3.1@aut-rails4/gems/rmagick-2.16.0 for inspection.
Results logged to /Users/neves/.rvm/gems/ruby-2.3.1@authorea-rails4/gems/rmagick-2.16.0/ext/RMagick/gem_make.out
Update brew at first
brew update
Then install imagemagic brew install imagemagick@6
Then config path and install rmagic gem
PKG_CONFIG_PATH=/usr/local/opt/imagemagick@6/lib/pkgconfig gem install rmagick