"koji regen-repo dist-test-build"  command fails,

kojid, kojira, httpd, postgresql are all running.
selinux is disabled

I debug the kojid and create_local_repo() not be exe, because pkglist is empty.
i can't find who create this file, and when it be created.

Have somebody got this problem ?
I find out some old articles from mail list, but all are not help!

=======================================================
        if os.path.getsize(pkglist) > 0:
            # don't call createrepo with an empty pkglist or it'll
            # add every Koji-managed rpm to the repodata
            self.create_local_repo(rinfo, arch, pkglist, groupdata, oldrepo)
========================================================

[eric@wenjia tasks]$ koji regen-repo dist-test-build
Regenerating repo for tag dist-test-build
Watching tasks (this may be safely interrupted)...
712 newRepo (dist-test-build): free
712 newRepo (dist-test-build): free -> open (kojibuilder1)
  714 createrepo (i386): free
  713 createrepo (x86_64): free
  715 createrepo (ia64): free
  713 createrepo (x86_64): free -> open (kojibuilder1)
  713 createrepo (x86_64): open (kojibuilder1) -> FAILED: Fault: <Fault 1: 'Traceback (most recent call last):\n  File "/usr/sbin/kojid", line 1285, in runTask\n    response = (handler.run(),)\n  File "/usr/sbin/kojid", line 1361, in run\n    return self.handler(*self.params,**self.opts)\n  File "/usr/sbin/kojid", line 2884, in handler\n    for f in os.listdir(self.datadir):\nOSError: [Errno 2] No such file or directory: \'/tmp/koji/tasks/713/713/repo/repodata\'\n'>
  2 free  1 open  0 done  1 failed
  714 createrepo (i386): free -> open (kojibuilder1)
  714 createrepo (i386): open (kojibuilder1) -> FAILED: Fault: <Fault 1: 'Traceback (most recent call last):\n  File "/usr/sbin/kojid", line 1285, in runTask\n    response = (handler.run(),)\n  File "/usr/sbin/kojid", line 1361, in run\n    return self.handler(*self.params,**self.opts)\n  File "/usr/sbin/kojid", line 2884, in handler\n    for f in os.listdir(self.datadir):\nOSError: [Errno 2] No such file or directory: \'/tmp/koji/tasks/714/714/repo/repodata\'\n'>
  1 free  1 open  0 done  2 failed
  715 createrepo (ia64): free -> canceled
  0 free  1 open  1 done  2 failed
712 newRepo (dist-test-build): open (kojibuilder1) -> FAILED: Fault: <Fault 1: 'Traceback (most recent call last):\n  File "/usr/sbin/kojid", line 1285, in runTask\n    response = (handler.run(),)\n  File "/usr/sbin/kojid", line 1361, in run\n    return self.handler(*self.params,**self.opts)\n  File "/usr/sbin/kojid", line 2884, in handler\n    for f in os.listdir(self.datadir):\nOSError: [Errno 2] No such file or directory: \'/tmp/koji/tasks/713/713/repo/repodata\'\n'>
  0 free  0 open  1 done  3 failed

712 newRepo (dist-test-build) failed