Why does snmp fail to use its own MIBs?

Solution 1:

apt-get install snmp-mibs-downloader

The above command downloads various non-free MIBs which the free MIBs (included with distro) require to work.

There are still a handful of errors, after installing this non-free package, but the snmpwalk now works.

Solution 2:

It seems you do not have snmp installed. Just do

sudo apt-get install snmp