there are several workarounds:
1) use debian (this is where bugs get fixed)
2) make some noise here, so that launchpad (canonical) can hear you
3) create the config by hand: net-snmp-create-v3-user is just a simple shell
script, that was forgotten to be packaged: the content translates to:
stop
Public bug reported:
# net-snmp-config --create-snmpv3-user
/usr/bin/net-snmp-config: 236: /usr/bin/net-snmp-config:
net-snmp-create-v3-user: not found
reference: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=726158
$ cat /tmp/apport.libsnmp-dev.0klis68z.apport
ProblemType: Bug
