5.02 GENERIC build fails

[steve%prd.co.uk@localhost (Steve Blinkhorn)]

I am having problems kernel building.  Architecture is GENERIC i386.
With the stock kernel config file and sources from a fresh .tgz,
things go wrong in ../../../../dist/ipf/netinet/fil.c:

In file included from ../../../../dist/ipf/netinet/fil.c:125:
../../../../netinet/ip_fil.h:572: error: expected declaration
specifiers or '...' before 'caddr_t'
../../../../netinet/ip_fil.h:627: error: expected ')' before 'int'
In file included from ../../../../dist/ipf/netinet/fil.c:126:
../../../../netinet/ip_nat.h:304: error: expected ')' before 'u_long'
In file included from ../../../../dist/ipf/netinet/fil.c:128:
../../../../netinet/ip_state.h:208: error: expected ')' before
'u_long'
In file included from ../../../../dist/ipf/netinet/fil.c:130:
../../../../netinet/ip_auth.h:59: error: expected ')' before 'int'

Wondering whether I need a new config executable, I grabbed the
sources for that, and:

mkheaders.c:58:24: error: crc_extern.h: No such file or directory
mkdep: compile failed.
*** Error code 1

All I wanted to do was build a custom kernel without the module for
usb scanners, so as to use libusb.  

Have I missed something?

-- 
Steve Blinkhorn <steve%prd.co.uk@localhost>