root@arrakis:~# 
root@arrakis:~# 
root@arrakis:~# cat /var/lib/gems/1.8/gems/rjb-1.1.2/ext/gem_make.out
ruby extconf.rb install rjb
*** 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=/usr/bin/ruby1.8
extconf.rb:36:in `open': No such file or directory - /usr/lib/jvm/java-6-sun/jre/include (Errno::ENOENT)
        from extconf.rb:36
root@arrakis:~# 
root@arrakis:~# echo $JAVA_HOME
/usr/lib/jvm/java-6-sun/jre
root@arrakis:~# 
root@arrakis:~# ll /usr/lib/jvm/java-6-sun/jre/
total 260
drwxr-xr-x  2 root root   4096 2008-03-19 12:00 bin
-rw-r--r--  1 root root   2487 2007-09-24 23:05 COPYRIGHT
drwxr-xr-x  2 root root   4096 2008-03-19 12:00 javaws
drwxr-xr-x 17 root root   4096 2008-03-19 12:00 lib
-rw-r--r--  1 root root  35120 2006-12-06 17:20 LICENSE
drwxr-xr-x  4 root root   4096 2008-03-19 02:38 man
drwxr-xr-x  4 root root   4096 2008-03-19 02:38 plugin
-rw-r--r--  1 root root  13543 2006-12-06 17:21 README
-rw-r--r--  1 root root 178596 2007-09-24 23:05 THIRDPARTYLICENSEREADME.txt
-rw-r--r--  1 root root    968 2007-09-24 23:05 Welcome.html
root@arrakis:~# 
root@arrakis:~#