vagrant gem install veewee failure

gem_make.out

/Applications/Vagrant/embedded/bin/ruby extconf.rb
checking for main() in -lc... *** 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
	--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=/Applications/Vagrant/embedded/bin/ruby
	--with-gherkin_lexer_ar-dir
	--without-gherkin_lexer_ar-dir
	--with-gherkin_lexer_ar-include
	--without-gherkin_lexer_ar-include=${gherkin_lexer_ar-dir}/include
	--with-gherkin_lexer_ar-lib
	--without-gherkin_lexer_ar-lib=${gherkin_lexer_ar-dir}/lib
	--with-clib
	--without-clib
/Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:455:in `block in try_link0'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/tmpdir.rb:83:in `mktmpdir'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:452:in `try_link0'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:476:in `try_link'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:619:in `try_func'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:845:in `block in have_library'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:254:in `open'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:254:in `open'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:280:in `postpone'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for'
	from /Applications/Vagrant/embedded/lib/ruby/1.9.1/mkmf.rb:840:in `have_library'
	from extconf.rb:5:in `<main>'

I don't think I understand this response to my previous gist.