title: Failed to build gem native extension in ubuntu?
body: <p>I am installing a gem in my <code>ubuntu</code> machine:</p>
  
  <pre><code>gem install tokyocabinet -v '1.29.1'
  </code></pre>
  
  <p>then I get some errors:</p>
  
  <pre><code>ERROR:  Error installing tokyocabinet:
      ERROR: Failed to build gem native extension.
  
      $HOME/.rvm/rubies/ruby-2.2.0/bin/ruby -r ./siteconf20150409-9995-bkqyu2.rb extconf.rb
  setting variables ...
    $CFLAGS = -I. -I/usr/local/include -Wall $(cflags)  -fPIC -O2
    $LDFLAGS = -L. -fstack-protector -rdynamic -Wl,-export-dynamic -L. -L/usr/local/lib
    $libs =  -ltokyocabinet -lz -lbz2 -lpthread -lm -lc
  checking for tcutil.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
      ...
  
  $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
  You have to install development tools first.
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:587:in `try_cpp'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:1066:in `block in have_header'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:917:in `block in checking_for'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:351:in `block (2 levels) in postpone'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:321:in `open'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:351:in `block in postpone'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:321:in `open'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:347:in `postpone'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:916:in `checking_for'
      from $HOME/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/mkmf.rb:1065:in `have_header'
      from extconf.rb:26:in `&lt;main&gt;'
  
  extconf failed, exit code 1
  
  Gem files will remain installed in $HOME/.rvm/gems/ruby-2.2.0/gems/tokyocabinet-1.29.1 for inspection.
  Results logged to $HOME/.rvm/gems/ruby-2.2.0/extensions/x86_64-linux/2.2.0/tokyocabinet-1.29.1/gem_make.out
  </code></pre>
  
  <p>it seems that it is something wrong with <code>try_cpp</code>, so it maybe because I do not install <code>gcc</code> or <code>g++</code>? But I do install them.</p>