```
$ show dhcpv6 server leases
Traceback (most recent call last):
File "/usr/libexec/vyos/op_mode/dhcp.py", line 427, in <module>
res = vyos.opmode.run(sys.modules[__name__])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/vyos/opmode.py", line 263, in run
res = func(**args)
^^^^^^^^^^^^
File "/usr/libexec/vyos/op_mode/dhcp.py", line 264, in _wrapper
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "/usr/libexec/vyos/op_mode/dhcp.py", line 317, in show_server_leases
lease_data = _get_raw_server_leases(family=family, pool=pool, sorted=sorted, state=state, origin=origin)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/libexec/vyos/op_mode/dhcp.py", line 108, in _get_raw_server_leases
data_lease['duid'] = _format_hex_string(lease.duid)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/libexec/vyos/op_mode/dhcp.py", line 54, in _format_hex_string
out_str = ':'.join(a+b for a,b in zip(in_str[::2], in_str[1::2]))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: sequence item 0: expected str instance, int found
```