I have migrated my old samba 3.6 NT domain to samba 4.2.2 with samba-tool classicupgrade. After I run sysvolcheck and see error:
# samba-tool ntacl sysvolcheck
ERROR(<type 'exceptions.TypeError'>): uncaught exception - (87, 'Attribute not found')
File "/usr/local/lib/python2.7/site-packages/samba/netcmd/init.py", line 175, in _run
return self.run(*args, **kwargs)
File "/usr/local/lib/python2.7/site-packages/samba/netcmd/ntacl.py", line 249, in run
lp)
File "/usr/local/lib/python2.7/site-packages/samba/provision/init.py", line 1717, in checksysvolacl
fsacl = getntacl(lp, dir_path, direct_db_access=direct_db_access, service=SYSVOL_SERVICE)
File "/usr/local/lib/python2.7/site-packages/samba/ntacls.py", line 73, in getntacl
xattr.XATTR_NTACL_NAME)

I see too few records in idmap.ldb:
#tdbtool /var/db/samba4/private/idmap.ldb
tdb> info
...
Number of records: 12
...

Because of this, sysvolreset doesn't work and I cannot assign properly fs ACL to sysvol. This looks like a bug.