cross-platform backup tool Rdiff-backup crashes when backing up to NFS (Devuan)

Hi all,

I've been using rdiff-backup without any problem now for years, but now 
I have one: I'm about to migrate a small server from Gentoo to Devuan. I 
got most of my stuff working, but my automated backup to an NFS share 
doesn't work. Rdiff-backup crashes.

I can't even backup a single file to the share:

     # cd
     # mkdir foo
     # touch foo/bar
     # rdiff-backup foo/ /nas/backup/test/
     Exception '[Errno 22] Invalid argument' raised of class '<class 
'OSError'>':
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
395, in error_check_Main
         Main(arglist)
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
417, in Main
         take_action(rps)
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
353, in take_action
         Backup(rps[0], rps[1])
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
442, in Backup
         backup.Mirror(rpin, rpout)
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
39, in Mirror
         DestS.patch(dest_rpath, source_diffiter)
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
269, in patch
         ITR(diff.index, diff)
     File "/usr/lib/python3/dist-packages/rdiff_backup/rorpiter.py", 
line 313, in __call__
         last_branch.fast_process(*args)
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
587, in fast_process
         if self.patch_to_temp(mirror_rp, diff_rorp, tf):
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
636, in patch_to_temp
         rpath.copy_attribs(diff_rorp, new)
     File "/usr/lib/python3/dist-packages/rdiff_backup/rpath.py", line 
238, in copy_attribs
         rpout.write_ea(rpin.get_ea())
     File "/usr/lib/python3/dist-packages/rdiff_backup/rpath.py", line 
1664, in write_ea
         ea.write_to_rp(self)
     File "/usr/lib/python3/dist-packages/rdiff_backup/eas_acls.py", 
line 131, in write_to_rp
         self.clear_rp(rp)
     File "/usr/lib/python3/dist-packages/rdiff_backup/eas_acls.py", 
line 106, in clear_rp
         rp.conn.xattr.remove(rp.path, name, rp.issym())

     Traceback (most recent call last):
     File "/usr/bin/rdiff-backup", line 32, in <module>
         rdiff_backup.Main.error_check_Main(sys.argv[1:])
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
395, in error_check_Main
         Main(arglist)
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
417, in Main
         take_action(rps)
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
353, in take_action
         Backup(rps[0], rps[1])
     File "/usr/lib/python3/dist-packages/rdiff_backup/Main.py", line 
442, in Backup
         backup.Mirror(rpin, rpout)
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
39, in Mirror
         DestS.patch(dest_rpath, source_diffiter)
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
269, in patch
         ITR(diff.index, diff)
     File "/usr/lib/python3/dist-packages/rdiff_backup/rorpiter.py", 
line 313, in __call__
         last_branch.fast_process(*args)
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
587, in fast_process
         if self.patch_to_temp(mirror_rp, diff_rorp, tf):
     File "/usr/lib/python3/dist-packages/rdiff_backup/backup.py", line 
636, in patch_to_temp
         rpath.copy_attribs(diff_rorp, new)
     File "/usr/lib/python3/dist-packages/rdiff_backup/rpath.py", line 
238, in copy_attribs
         rpout.write_ea(rpin.get_ea())
     File "/usr/lib/python3/dist-packages/rdiff_backup/rpath.py", line 
1664, in write_ea
         ea.write_to_rp(self)
     File "/usr/lib/python3/dist-packages/rdiff_backup/eas_acls.py", 
line 131, in write_to_rp
         self.clear_rp(rp)
     File "/usr/lib/python3/dist-packages/rdiff_backup/eas_acls.py", 
line 106, in clear_rp
         rp.conn.xattr.remove(rp.path, name, rp.issym())
     OSError: [Errno 22] Invalid argument

Using the very same share on another machine (running Gentoo and Artix) 
letting rdiff-backup make some backup to it works without a problem, so 
I suppose my NFS server is okay, and this is some Devuan (and also 
Debian?) specific problem.

I'm a bit out of ideas now ... can anybody help me? Thanks in advance!

Cheers, Tobias