On ubuntu 8.04 LTS I had to install the following packages which were not checked during gonfigure :
libsnmp-dev (libsnmp-base which includes net-snmp-config is not enough...)
flex (docsis-0.9.6/src/docsis_lex.c:1734: undefined reference to `yywrap')
PS : I also had to patch /usr/include/net-snmp/library/container.h to add some includes :
/usr/include/net-snmp/library/container.h:480: error: implicit declaration of function "strcmp"
/usr/include/net-snmp/library/container.h:429: error: implicit declaration of function "free"
Don't know if you can do something about that or if it is a real error from ubuntu.