title: Install Mongrel in Ruby 1.9.3
body: <p>How can I successfully install Mongrel for ruby 1.9.3</p>
  
  <p>Here's the error:</p>
  
  <pre><code>Building native extensions.  This could take a while...
  ERROR:  Error installing mongrel:
      ERROR: Failed to build gem native extension.
  
          /usr/bin/ruby1.9.1 extconf.rb
  checking for main() in -lc... yes
  creating Makefile
  
  make
  compiling http11_parser.c
  compiling http11.c
  http11.c: In function ‘http_field’:
  http11.c:70:3: error: format not a string literal and no format arguments [-Werror=format-security]
  http11.c:71:3: error: format not a string literal and no format arguments [-Werror=format-security]
  http11.c:77:22: error: ‘struct RString’ has no member named ‘ptr’
  http11.c:77:50: error: ‘struct RString’ has no member named ‘len’
  http11.c:77:27: warning: left-hand operand of comma expression has no effect [-Wunused-value]
  http11.c: In function ‘request_uri’:
  http11.c:102:3: error: format not a string literal and no format arguments [-Werror=format-security]
  http11.c: In function ‘fragment’:
  http11.c:113:3: error: format not a string literal and no format arguments [-Werror=format-security]
  http11.c: In function ‘request_path’:
  http11.c:124:3: error: format not a string literal and no format arguments [-Werror=format-security]
  http11.c: In function ‘query_string’:
  http11.c:135:3: error: format not a string literal and no format arguments [-Werror=format-security]
  http11.c: In function ‘header_done’:
  http11.c:172:13: error: ‘struct RString’ has no member named ‘ptr’
  http11.c:172:13: error: ‘struct RString’ has no member named ‘ptr’
  http11.c:172:13: error: ‘struct RString’ has no member named ‘ptr’
  http11.c:174:89: error: ‘struct RString’ has no member named ‘ptr’
  http11.c:176:52: error: ‘struct RString’ has no member named ‘ptr’
  http11.c:177:26: error: ‘struct RString’ has no member named ‘len’
  http11.c: In function ‘HttpParser_execute’:
  http11.c:298:23: error: ‘struct RString’ has no member named ‘ptr’
  http11.c:299:23: error: ‘struct RString’ has no member named ‘len’
  http11.c:307:5: error: format not a string literal and no format arguments [-Werror=format-security]
  cc1: some warnings being treated as errors
  make: *** [http11.o] Error 1
  
  
  Gem files will remain installed in /var/lib/gems/1.9.1/gems/mongrel-1.1.5 for inspection.
  Results logged to /var/lib/gems/1.9.1/gems/mongrel-1.1.5/ext/http11/gem_make.out
  </code></pre>
  
  <p>I already tried <code>sudo gem install mongrel --pre</code>
  and even the one that has <code>--source</code></p>
  
  <p>I don't know why it isn't working. Is it compatible with Ruby 1.9.1 and up?</p>