'sudo gem install screengif' fails on OS X 10.11

[jonathan8464]

Hey,

Thanks for the tool. I'm trying to install it using the instructions, and I get this when I do sudo gem install screengif. How do I install "development tools", as it says in the output?

Building native extensions.  This could take a while...
ERROR:  Error installing screengif:
	ERROR: Failed to build gem native extension.

    /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
checking for xcrun... yes
checking for Magick-config... no
checking for pkg-config... yes
checking for outdated ImageMagick version (<= 6.4.9)... no
checking for presence of MagickWand API (ImageMagick version >= 6.9.0)... no
checking for Ruby version >= 1.8.5... yes
checking for stdint.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.

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=/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:434:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:549:in `block in try_compile'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:502:in `with_werror'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:549:in `try_compile'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:1038:in `block in have_header'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:889:in `block in checking_for'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:340:in `block (2 levels) in postpone'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:310:in `open'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:340:in `block in postpone'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:310:in `open'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:336:in `postpone'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:888:in `checking_for'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:1037:in `have_header'
	from extconf.rb:39:in `configure_headers'
	from extconf.rb:18:in `initialize'
	from extconf.rb:548:in `new'
	from extconf.rb:548:in `<main>'


Gem files will remain installed in /Library/Ruby/Gems/2.0.0/gems/rmagick-2.16.0 for inspection.
Results logged to /Library/Ruby/Gems/2.0.0/gems/rmagick-2.16.0/ext/RMagick/gem_make.out

[dergachev]

Googling the error message, it seems related to not having xcode, or maybe it's out of date.

Maybe this is the command you need to run:
xcode-select --install

Good luck.

http://stackoverflow.com/questions/13963404/rails-and-os-x-how-to-install-rmagick
http://stackoverflow.com/questions/13279856/the-compiler-failed-to-generate-an-executable-file-runtimeerror

[spiritphyz]

Homebrew now installs Imagemagick 7, which doesn't work with Rmagick.

Installing Imagemagick 6 allows the install of screengif to work.
rmagick/rmagick#256 (comment)

brew install imagemagick@6
PKG_CONFIG_PATH=/usr/local/opt/imagemagick@6/lib/pkgconfig gem install rmagick
gem install screengif