当我执行 exe 命令 gem install rails 时出现错误
Temporarily enhancing PATH to include DevKit...
Building native extensions.  This could take a while...
ERROR:  Error installing rails:
        ERROR: Failed to build gem native extension.
C:/Ruby193/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=C:/Ruby193/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}/lib
C:/Ruby193/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to genera
te an executable file. (RuntimeError)
You have to install development tools first.
        from C:/Ruby193/lib/ruby/1.9.1/mkmf.rb:461:in `try_link0'
        from C:/Ruby193/lib/ruby/1.9.1/mkmf.rb:712:in `try_run'
        from extconf.rb:26:in `<main>'
Gem files will remain installed in C:/Ruby193/lib/ruby/gems/1.9.1/gems/atomic-1.
1.14 for inspection.
Results logged to C:/Ruby193/lib/ruby/gems/1.9.1/gems/atomic-1.1.14/ext/gem_make
.out