package libsnmp-base 5.8+dfsg-2ubuntu2 failed to install/upgrade: conffile difference visualizer subprocess returned error exit status 127

upgrading from 18.04 to 20.04

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: libsnmp-base 5.8+dfsg-2ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-106.107-generic 4.15.18
Uname: Linux 4.15.0-106-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.2
Architecture: amd64
CasperMD5CheckResult: skip
Date: Tue Jun 9 23:15:26 2020
Dependencies:

ErrorMessage: conffile difference visualizer subprocess returned error exit status 127
InstallationDate: Installed on 2018-07-03 (707 days ago)
InstallationMedia: Ubuntu-Server 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
Python3Details: /usr/bin/python3.8, Python 3.8.2, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: /usr/bin/python2.7, Python 2.7.18rc1, python-is-python2, 2.7.17-4
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.2ubuntu0.1
SNMPVersion:
 NET-SNMP version: 5.8
 Web: http://www.net-snmp.org/
 Email: <email address hidden>
SourcePackage: net-snmp
SyslogSnmptrapd:

Title: package libsnmp-base 5.8+dfsg-2ubuntu2 failed to install/upgrade: conffile difference visualizer subprocess returned error exit status 127
UpgradeStatus: Upgraded to focal on 2020-06-10 (0 days ago)
modified.conffile..etc.snmp.snmp.conf:
 # As the snmp packages come without MIB files due to license reasons, loading
  # of MIBs is disabled by default. If you added the MIBs you can reenable
  # loading them by commenting out the following line.
  #mibs :
modified.conffile..etc.snmp.snmpd.conf: [modified]
mtime.conffile..etc.snmp.snmp.conf: 2018-08-28T16:37:28.725632
mtime.conffile..etc.snmp.snmpd.conf: 2018-08-28T16:37:28.725632