image class got error from copyhardlinktree/tar during migration to whinlatter

Hi,

I'm working on uprev for a layer from scarthgap to whinlatter. In the 
layer there is a custom image class that will take part om the rootfs 
and make a separate image of. First step is to copy out that part to a 
separate directory before creating an image file. The function is using 
copyhardlinktree from 'meta/lib/oe/path.py'. It has worked well in 
scarthgap but when building in whinlatter I get this error:

              0106:
              0107:    _from = 
os.path.realpath(os.path.join(d.getVar("IMAGE_ROOTFS"), "data"))
              0108:    _to = 
os.path.realpath(os.path.join(d.getVar("WORKDIR"), "data.copy.%s" % 
d.getVar('BB_CURRENTTASK')))
              0109:
          *** 0110:    copyhardlinktree(_from, _to)
              0111:
         ...
         Subprocess output:
         tar: ./mydir: Cannot change ownership to uid 0, gid 0: Invalid 
argument
         tar: .: Cannot change ownership to uid 0, gid 0: Invalid argument
         tar: Exiting with failure status due to previous errors

The directory 'mydir' is owned by root user in my target file system. I 
would like to check if someone have seen similar things when going to 
newer versions? Or if someone have an idea about the root cause? I did a 
workaround and used 'shutil.copytree' to avoid this error but is curios 
to find the root cause and understand why it fails.

Best regards,
/Peter