RMagick build error...please help

Hi,

I’m trying to install RMagick and i’got this error :

[root@localhost RMagick-1.14.1]# make
if test -n “”; then
RUBYLIBDIR=–rbdir="";
fi;
if test -n “”; then
RUBYARCHDIR=–sodir="";
fi;
/usr/bin/ruby setup.rb config $RUBYLIBDIR $RUBYARCHDIR
—> lib
—> lib/rvg
<— lib/rvg
<— lib
—> ext
—> ext/RMagick
/usr/bin/ruby
/home/[user]appli/tmp/RMagick-1.14.1/ext/RMagick/extconf.rb
can’t find header files for ruby.
setup.rb:655:in command': system("/usr/bin/ruby" "/home/[user]/appli/tmp/RMagick-1.14.1/ext/RMagick/extconf.rb") failed (RuntimeError) from setup.rb:660:inruby’
from setup.rb:1238:in extconf' from setup.rb:1230:inconfig_dir_ext’
from setup.rb:1532:in __send__' from setup.rb:1532:intraverse’
from setup.rb:1549:in dive_into' from setup.rb:1530:intraverse’
from setup.rb:1534:in traverse' ... 9 levels... from setup.rb:826:insend
from setup.rb:826:in invoke' from setup.rb:772:ininvoke’
from setup.rb:1578
make: *** [.config] Erreur 1

i’ve build image magick whithout error

what’s wrong in my system ?

thx

my problem is solved
i install ruby-devel package ans it’s ok