* Package:    dev-ruby/ruby-shadow-2.4.1
 * Repository: gentoo
 * Maintainer: ruby@gentoo.org
 * USE:        abi_x86_64 amd64 elibc_glibc kernel_linux ruby_targets_ruby20 ruby_targets_ruby21 userland_GNU
 * FEATURES:   preserve-libs sandbox userpriv usersandbox
>>> Unpacking source...
 * Running unpack phase for all ...
 * Unpacking .gem file... ...
 [ ok ]
 * Uncompressing metadata ...
 [ ok ]
 * Unpacking data.tar.gz ...
 [ ok ]
>>> Source unpacked in /var/tmp/portage/dev-ruby/ruby-shadow-2.4.1/work
>>> Preparing source in /var/tmp/portage/dev-ruby/ruby-shadow-2.4.1/work ...
 * Running prepare phase for all ...
 * Running source copy phase for ruby20 ...
 * Running source copy phase for ruby21 ...
>>> Source prepared.
>>> Configuring source in /var/tmp/portage/dev-ruby/ruby-shadow-2.4.1/work ...
 * Running configure phase for ruby20 ...
checking for getspent() in -lshadow... no
checking for getspent()... yes
checking for fgetspent()... yes
checking for setspent()... yes
checking for endspent()... yes
checking for lckpwdf()... yes
checking for ulckpwdf()... yes
checking for sgetspent()... yes
checking for ruby/io.h... yes
creating Makefile
 * Running configure phase for ruby21 ...
checking for getspent() in -lshadow... *** 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}/lib64
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/usr/bin/ruby21
	--with-shadowlib
	--without-shadowlib
/usr/lib64/ruby/2.1.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
	from /usr/lib64/ruby/2.1.0/mkmf.rb:541:in `try_link0'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:556:in `try_link'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:736:in `try_func'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:967:in `block in have_library'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:912:in `block in checking_for'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:351:in `block (2 levels) in postpone'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:321:in `open'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:351:in `block in postpone'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:321:in `open'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:347:in `postpone'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:911:in `checking_for'
	from /usr/lib64/ruby/2.1.0/mkmf.rb:962:in `have_library'
	from extconf.rb:31:in `<main>'
 * ERROR: dev-ruby/ruby-shadow-2.4.1::gentoo failed (configure phase):
 *   Configuration failed.
 * 
 * Call stack:
 *     ebuild.sh, line   90:  Called src_configure
 *   environment, line 4303:  Called ruby-ng_src_configure
 *   environment, line 3995:  Called _ruby_each_implementation 'each_ruby_configure'
 *   environment, line  465:  Called _ruby_invoke_environment 'ruby21' 'each_ruby_configure'
 *   environment, line  560:  Called each_ruby_configure
 *   environment, line  844:  Called die
 * The specific snippet of code:
 *       ${RUBY} extconf.rb || die "Configuration failed.";
 * 
 * If you need support, post the output of `emerge --info '=dev-ruby/ruby-shadow-2.4.1::gentoo'`,
 * the complete build log and the output of `emerge -pqv '=dev-ruby/ruby-shadow-2.4.1::gentoo'`.
!!! When you file a bug report, please include the following information:
GENTOO_VM=  CLASSPATH="" JAVA_HOME=""
JAVACFLAGS="" COMPILER=""
and of course, the output of emerge --info =ruby-shadow-2.4.1
 * The complete build log is located at '/var/log/portage/dev-ruby:ruby-shadow-2.4.1:20150930-170943.log'.
 * For convenience, a symlink to the build log is located at '/var/tmp/portage/dev-ruby/ruby-shadow-2.4.1/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/dev-ruby/ruby-shadow-2.4.1/temp/environment'.
 * Working directory: '/var/tmp/portage/dev-ruby/ruby-shadow-2.4.1/work/ruby21/ruby-shadow-2.4.1'
 * S: '/var/tmp/portage/dev-ruby/ruby-shadow-2.4.1/work/ruby21/ruby-shadow-2.4.1'