install error: unable to read package metadata

[Gianluca Cecchi]

I'm trying to install via pxe+nfs from rsync of yesterday on x86 and I
get this error window during anaconda:
unable to read package metadata. this may be due
to a missing repodata. Please ensure that your
install tree has been correctly
generated. failure: repodata/comps.xml  from anaconda:
[errno 256] no more mirrors to try
switching to the shell with Ctrl+Alt+F2, I see inside anaconda.log in
/tmp I have
[snip]
10:42:24 INFO    : NFS install method detected, will use RHupdates/
10:42:24 INFO    : Running anaconda script /usr/bin/anaconda
10:42:27 INFO    : Display mode = g
10:42:27 INFO    : Method = nfs://mnt/source/.
10:42:44 INFO    : Started mini-wm
10:42:44 INFO    : Starting graphical installation...
10:42:45 INFO    : anaconda floppy device None
10:42:45 DEBUG   : self.driveList(): ['sda', 'sdb']
10:42:45 DEBUG   : DiskSet.skippedDisks: []
10:42:45 DEBUG   : DiskSet.skippedDisks: []
10:42:45 DEBUG   : starting all dmraids on drives ['sda', 'sdb']
10:42:45 DEBUG   : scanning for dmraid on drives ['sda', 'sdb']
10:42:45 WARNING : Couldnt lookup monitor type Smart Cable.
10:42:45 WARNING : step partitionmethod does not exist
10:42:45 WARNING : step partitionmethodsetup does not exist
10:42:45 WARNING : step autopartition does not exist
10:42:45 WARNING : step readcomps does not exist
10:42:45 WARNING : step selectlangpackages does not exist
10:42:45 WARNING : step handleX11pkgs does not exist
10:42:45 WARNING : step handlemiscpkgs does not exist
10:42:45 WARNING : step fixupconditionals does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:45 WARNING : step complete does not exist
10:42:46 INFO    : moving (1) to step partitionobjinit
10:42:46 DEBUG   : self.driveList(): ['sda', 'sdb']
10:42:46 DEBUG   : DiskSet.skippedDisks: []
10:42:46 DEBUG   : DiskSet.skippedDisks: []
10:42:46 INFO    : moving (1) to step autopartitionexecute
10:42:46 INFO    : moving (1) to step partitiondone
10:42:46 INFO    : moving (1) to step bootloadersetup
10:42:46 INFO    : moving (1) to step networkdevicecheck
10:42:46 INFO    : moving (1) to step reposetup
10:42:47 INFO    : anaconda
        [1/1]
10:42:47 ERROR   : reading package metadata: failure:
repodata/comps.xml from anaconda: [Errno 256] No more mirrors to try.

df -k gives:
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev                   1948452         0   1948452   0% /dev
192.168.0.110:/fc5nfs
                      14200000   9822368   3644672  73% /mnt/source
/tmp/loop0               70720     70720         0 100% /mnt/runtime
 and I can edit /mnt/source/repodata/comps.xml ....

Is this a problem on my part about rsync or what?
How can I dig into this?