Failed to commit SNMPd extended custom scripts

When I try to configure the extension in the snmpd service, an error occurs during the commit.

user@router# set service snmp script-extensions extension-name helloscript script my_script.sh
[edit]
user@router# commit
[ service snmp ]
VyOS had an issue completing a command.

We are sorry that you encountered a problem while using VyOS.
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- Make sure you are running the latest version of the code available at
  https://downloads.vyos.io/rolling/current/amd64/vyos-rolling-latest.iso
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Report Time:      2020-09-25 15:38:18
Image Version:    VyOS 1.3-rolling-202009250118
Release Train:    equuleus

Built by:         autobuild@vyos.net
Built on:         Fri 25 Sep 2020 01:18 UTC
Build UUID:       0e6091f1-2ade-4089-a2d6-7a0e1f3618e7
Build Commit ID:  d571b383797719

Architecture:     x86_64
Boot via:         installed image
System type:      VMware guest

Hardware vendor:  VMware, Inc.
Hardware model:   VMware Virtual Platform
Hardware S/N:     VMware-42 05 73 e1 21 ad 58 4e-94 ae 30 8f b7 2d 46 c3
Hardware UUID:    420573e1-21ad-584e-94ae-308fb72d46c3

Traceback (most recent call last):
  File "/usr/libexec/vyos/conf_mode/snmp.py", line 576, in <module>
    verify(c)
  File "/usr/libexec/vyos/conf_mode/snmp.py", line 397, in verify
    chmod_755(ext['script'])
NameError: name 'chmod_755' is not defined

[[service snmp]] failed
Commit failed
[edit]

Thanks for the report.

This task and associated PR should correct it