root@accuvantlabs:/opt/metasploit/msf3# msfconsole
[-] Failed to connect to the database: Please install the postgresql adapter: `gem install activerecord-postgresql-adapter` (no such file to load -- pg_ext) {"adapter"=>"postgresql", "database"=>"msf3dev", "username"=>"msf3", "password"=>"20394965", "port"=>7337, "host"=>"localhost", "pool"=>256, "timeout"=>5} ["/opt/metasploit/msf3/lib/active_record/connection_adapters/abstract/connection_specification.rb:76:in `rescue in rescue in establish_connection'", "/opt/metasploit/msf3/lib/active_record/connection_adapters/abstract/connection_specification.rb:73:in `rescue in establish_connection'", "/opt/metasploit/msf3/lib/active_record/connection_adapters/abstract/connection_specification.rb:68:in `establish_connection'", "/opt/metasploit/msf3/lib/msf/core/db_manager.rb:155:in `connect'", "/opt/metasploit/msf3/lib/msf/ui/console/driver.rb:195:in `initialize'", "/opt/metasploit/msf3/msfconsole:134:in `new'", "/opt/metasploit/msf3/msfconsole:134:in `<main>'"]

     ,           ,
    /             \
   ((__---,,,---__))
      (_) O O (_)_________
         \ _ /            |\
          o_o \   M S F   | \
               \   _____  |  *
                |||   WW|||
                |||     |||


       =[ metasploit v4.3.0-dev [core:4.3 api:1.0]
+ -- --=[ 813 exploits - 458 auxiliary - 137 post
+ -- --=[ 247 payloads - 27 encoders - 8 nops
       =[ svn r14910 updated today (2012.03.10)

msf > gem install pg -- --with-pg-config=/opt/metasploit/postgresql/bin/pg_config
[*] exec: gem install pg -- --with-pg-config=/opt/metasploit/postgresql/bin/pg_config

Building native extensions.  This could take a while...
ERROR:  Error installing pg:
	ERROR: Failed to build gem native extension.

/opt/metasploit/ruby/bin/ruby extconf.rb --with-pg-config=/opt/metasploit/postgresql/bin/pg_config
mkmf.rb can't find header files for ruby at /opt/metasploit/ruby/lib/ruby/include/ruby.h


Gem files will remain installed in /opt/metasploit/ruby/lib/ruby/gems/1.9.1/gems/pg-0.13.2 for inspection.
Results logged to /opt/metasploit/ruby/lib/ruby/gems/1.9.1/gems/pg-0.13.2/ext/gem_make.out
msf > exit