gem install activerecord --no-ri --no-rdoc Building native extensions. This could take a while... ERROR: Error installing activerecord: ERROR: Failed to build gem native extension.

g:/Ruby20/bin/ruby.exe extconf.rb *** 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=g:/Ruby20/bin/ruby --with-atomic_reference-dir --without-atomic_reference-dir --with-atomic_reference-include --without-atomic_reference-include=${atomic_reference-dir}/include --with-atomic_reference-lib --without-atomic_reference-lib=${atomic_reference-dir}/ g:/Ruby20/lib/ruby/2.0.0/mkmf.rb:431:in try_do': The compiler failed to generate an executable file. (RuntimeError) You have to install development tools first. from g:/Ruby20/lib/ruby/2.0.0/mkmf.rb:516:intry_link0' from g:/Ruby20/lib/ruby/2.0.0/mkmf.rb:814:in try_run' from extconf.rb:24:in

Gem files will remain installed in g:/Ruby20/lib/ruby/gems/2.0.0/gems/atomic-1.1.13 for inspection. Results logged to g:/Ruby20/lib/ruby/gems/2.0.0/gems/atomic-1.1.13/ext/gem_make.out