gem install tiny_tds --platform=ruby
Building native extensions.  This could take a while...
ERROR:  Error installing tiny_tds:
        ERROR: Failed to build gem native extension.

    /usr/bin/ruby.exe -r ./siteconf20141121-704-1t0earj.rb extconf.rb
checking for iconv_open() in iconv.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=/usr/bin/ruby
        --enable-lookup
        --disable-lookup
        --with-iconv-dir
        --without-iconv-dir
        --with-iconv-include
        --without-iconv-include=${iconv-dir}/include
        --with-iconv-lib
        --without-iconv-lib=${iconv-dir}/
        --with-freetds-dir
        --without-freetds-dir
        --with-freetds-include
        --without-freetds-include=${freetds-dir}/include
        --with-freetds-lib
        --without-freetds-lib=${freetds-dir}/
/usr/share/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 /usr/share/ruby/2.0.0/mkmf.rb:519:in `try_link0'
        from /usr/share/ruby/2.0.0/mkmf.rb:534:in `try_link'
        from /usr/share/ruby/2.0.0/mkmf.rb:720:in `try_func'
        from /usr/share/ruby/2.0.0/mkmf.rb:1004:in `block in have_func'
        from /usr/share/ruby/2.0.0/mkmf.rb:895:in `block in checking_for'
        from /usr/share/ruby/2.0.0/mkmf.rb:340:in `block (2 levels) in postpone'
        from /usr/share/ruby/2.0.0/mkmf.rb:310:in `open'
        from /usr/share/ruby/2.0.0/mkmf.rb:340:in `block in postpone'
        from /usr/share/ruby/2.0.0/mkmf.rb:310:in `open'
        from /usr/share/ruby/2.0.0/mkmf.rb:336:in `postpone'
        from /usr/share/ruby/2.0.0/mkmf.rb:894:in `checking_for'
        from /usr/share/ruby/2.0.0/mkmf.rb:1003:in `have_func'
        from extconf.rb:94:in `<main>'

extconf failed, exit code 1