compile problem with sysctl.h

[Fede b]

hi all,
when i try to compile BIND 8.2.2-P5 version, in particular
when i do a "make depend", it says:
" cfe: Error: noop.c: 13: Cannot open file sys/sysctl.h for #include"
I don't have it in my irix 6.2 system.
Any idea??
Tahnks all
Federico.