[root@frodo zaptel-1.0.2]# make
cc -I. -O4 -g -Wall -DBUILDING_TONEZONE    -DSTANDALONE_ZAPATA -DZAPTEL_CONFIG=\"/etc/zaptel.conf\"   -c -o gendigits.o gendigits.c
cc -o gendigits gendigits.o -lm
./gendigits
gcc -I/usr/src/linux-2.4/include -O6 -DMODULE -D__KERNEL__ -DEXPORT_SYMTAB -I/usr/src/linux/drivers/net -Wall -I. -Wstrict-prototypes -fomit-frame-pointer -I/usr/src/linux/drivers/net/wan -I /usr/src/linux/include -I/usr/src/linux/include/net   -DSTANDALONE_ZAPATA -c zaptel.c
In file included from /usr/include/linux/module.h:20,
                 from zaptel.c:44:
/usr/include/linux/modversions.h:1:2: #error Modules should never use kernel-headers system headers,
/usr/include/linux/modversions.h:2:2: #error but rather headers from an appropriate kernel-source package.
/usr/include/linux/modversions.h:3:2: #error Change -I/usr/src/linux/include (or similar) to
/usr/include/linux/modversions.h:4:2: #error -I/lib/modules/$(uname -r)/build/include
/usr/include/linux/modversions.h:5:2: #error to build against the currently-running kernel.
make: *** [zaptel.o] Error 1