cygwin rcs 5.7?

[Hugh Sasse Staff Elec Eng]

Attempting to build rcs under cygwin gives:

OK
mv a.h conf.h
rm -f a.* core core.* *.core
gcc -c  -Dhas_conf_h  -I. -I. -g -O ci.c
gcc -c  -Dhas_conf_h  -I. -I. -g -O rcslex.c
rcslex.c: In function `I_open':
rcslex.c:1117: `type' undeclared (first use in this function)
rcslex.c:1117: (Each undeclared identifier is reported only once
rcslex.c:1117: for each function it appears in.)
make[1]: *** [rcslex.o] Error 1
make[1]: Leaving directory `/cygdrive/c/Hugh/rcs-5.7/src'
make: *** [all] Error 2

address@hidden ~/rcs-5.7

What should I be looking for now?
        Hugh