Exception while installing rails - ruby-on-rails

Question

I am getting following exception while installing rails in Opensuse.
Version of Ruby is ruby 2.1.3p242 (2014-09-19 revision 47630) [x86_64-linux-gnu]
/usr/lib64/ruby/gems/2.1.0/gems/nokogiri-1.6.8/test/xslt/test_custom_functions.rb
/usr/lib64/ruby/gems/2.1.0/gems/nokogiri-1.6.8/test/xslt/test_exception_handling.rb
/usr/lib64/ruby/gems/2.1.0/gems/nokogiri-1.6.8/test_all
Building native extensions. This could take a while...
current directory: /usr/lib64/ruby/gems/2.1.0/gems/nokogiri-1.6.8/ext/nokogiri
/usr/bin/ruby.ruby2.1 -r ./siteconf20160625-7943-34np6o.rb extconf.rb
Using pkg-config version 1.1.7
checking if the C compiler accepts ... *** 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/ruby.ruby2.1
--help
--clean
/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:571:in `block in try_compile'
from /usr/lib64/ruby/2.1.0/mkmf.rb:522:in `with_werror'
from /usr/lib64/ruby/2.1.0/mkmf.rb:571:in `try_compile'
from extconf.rb:138:in `nokogiri_try_compile'
from extconf.rb:162:in `block in add_cflags'
from /usr/lib64/ruby/2.1.0/mkmf.rb:621:in `with_cflags'
from extconf.rb:161:in `add_cflags'
from extconf.rb:414:in `<main>'
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
Building has failed. See above output for more information on the failure.
To see why this extension failed to compile, please check the mkmf.log which can be found here:
/usr/lib64/ruby/gems/2.1.0/extensions/x86_64-linux/2.1.0/nokogiri-1.6.8/mkmf.log
extconf failed, exit code 1
Content of mkmf.log is follows:
gcc -o conftest -I/usr/include/ruby-2.1.0/x86_64-linux-gnu -I/usr/include /ruby-2.1.0/ruby/backward -I/usr/include/ruby-2.1.0 -I. -fmessage-length=0 -grecord-gcc-switches -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables -fasynchronous-unwind-tables -g -fno-strict-aliasing -fPIC conftest.c -L. -L/usr/lib64 -L. -fstack-protector -rdynamic -Wl,-export-dynamic -lruby2.1 -lpthread -ldl -lcrypt -lm -lc "
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: int main(int argc, char **argv)
4: {
5: return 0;
6: }
/* end */