Puppet master, symlink and SELinux

I created a puppet module p4 under my home folder and symlinked the module folder into /etc/puppet/modules. I can run sudo puppet apply test.pp succefully on the master, but when I ran

sudo puppet agent --no-daemonize --verbose --onetime

on an agent machine, I got the following error:

err: Could not retrieve catalog from remote server: Error 400 on SERVER: Could not find class p4 at /etc/puppet/manifests/nodes.pp:2 on node pslave1.puppet-test.com

This page is helpful: http://groups.google.com/group/puppet-users/browse_thread/thread/66361418d801a97c. But my situation is different, the permission of module folders is rwxrwxr-x. I ran this command

sudo strace -e trace=file -f puppet master --no-daemonize --debug 2>&1 | tee log

It turned out that there WAS a "permission denied" issue:

[pid 15508] stat("/etc/puppet/modules/p4", 0x7fff44cfb630) = -1 EACCES (Permission denied)

After I copied p4 folder to /usr/share/puppet/modules, everything worked. SELinux is installed on my CentOS. It must be SELinux that blocks puppet to access the file.