why su -c 'yum install rpmdevtools' Processing Dependency failed ?

[xkdcc]

I want to build my kernel on Fedora.
But when I install rpmdevtolls in advanced, I met problems:
# uname -a
# Linux fdvm.brantdomain 2.6.18-1.2798.fc6 #1 SMP x86_64 GNU/Linux
# yum install rpmdevtools
 ......
Error: --> Processing Dependency: elfutils-libelf = 0.123-1.fc6 package: elfutils-libelf-devel
--> Finished Dependency Resolution
Error: elfutils-libelf conflicts with elfutils > 0.123-1.fc6
Error: elfutils-libelf conflicts with elfutils-libs > 0.123-1.fc6
Error: Missing Dependency: elfutils-libelf = 0.123-1.fc6 is needed by package elfutils-libelf-devel
Please help me out. Thanks.