Anyone has a webrick server which works with a cgi test file, to share
with me?
Hopefully, not all webrick users are at the rails conference!

I have tried various combinations with various errors. Here is the
latest attempt
using the info on this page for server and test file
http://microjet.ath.cx/webrickguide/html/CGIHandler.html
----------------->
require 'webrick'

include WEBrick    # let's import the namespace so
                   # I don't have to keep typing
                   # WEBrick:: in this documentation.

def start_webrick(config = {})
  # always listen on port 8080
  config.update(:Port => 8080)
  server = HTTPServer.new(config)
  yield server if block_given?
  ['INT', 'TERM'].each {|signal|
    trap(signal) {server.shutdown}
  }
  server.start

end

start_webrick {|server|
  cgi_dir = '/library/webserver/documents/ruby/cgi-bin'
  server.mount('/cgi-bin', HTTPServlet::FileHandler, cgi_dir,
    {:FancyIndexing=>true})
}

with the test file in cgi-bin, test2.cgi, executable
#!/usr/bin/env ruby
print "Content-type: text/plain\r\n\r\n"
ENV.keys.sort.each{|k| puts "#{k} ==> #{ENV[k]}"}

I get an error message.
env: ruby: No such file or directory
With other attempts I get other errors.

I started with the webserver on this page
http://microjet.ath.cx/webrickguide/html/What_is_WEBrick.html
---------------->
require 'webrick'

include WEBrick    # let's import the namespace so
                   # I don't have to keep typing
                   # WEBrick:: in this documentation.

def start_webrick(config = {})
  # always listen on port 8080
  config.update(:Port => 8080)
  server = HTTPServer.new(config)
  yield server if block_given?
  ['INT', 'TERM'].each {|signal|
    trap(signal) {server.shutdown}
  }
  server.start

end

start_webrick(:DocumentRoot =>
'/library/webserver/documents/ruby/cgi-bin')
----------------------
it serves a hello.html file in cgi-bin directory fine.
----------------->
<!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN">
<HTML>
   <HEAD>
      <TITLE>
         A Small Hello
      </TITLE>
   </HEAD>
<BODY>
   <H1>Hi</H1>
   <P>This is very minimal "hello world" HTML document.</P>
</BODY>
</HTML>