[oclug] make trouble

[Dave]

Hey Gang,

I've got another case of `I know where it is, but the Makefile doesn't.' 
The short Makefile:
CC        = gcc
CFLAGS    = -g -O2 -Wall
XROOT     = /usr/X11R6
INCLUDES  = -I$(XROOT)/include  
LIBS      = -lX11 -lXext -lXpm
LDPATH    = -L$(XROOT)/lib

PROG      = oroborus
RCFILE    = .$(PROG)rc
DEFINES   = -DSHAPE_SUPPORT -DWORKSPACE_SUPPORT #-DDEBUG
PREFIX    = /usr
DATADIR   = $(PREFIX)/share/$(PROG)
PIXMAPDIR = $(DATADIR)/pixmaps/default

HEADERS   = $(PROG).h
OBJS      = $(PROG).o client.o events.o workspace.o config.o hints.o misc.
o 

all: $(PROG) 

$(PROG): $(OBJS)
	$(CC) $(OBJS) $(LDPATH) $(LIBS) -o $@

$(OBJS): %.o: %.c $(HEADERS)
	$(CC) $(CFLAGS) -DRCFILE=\"$(RCFILE)\" -DPIXMAPDIR=\"$(PIXMAPDIR)\
" $(DEFINES) $(INCLUDES) -c $< -o $@
<and so on and so on>
---------------------------------------
make complains,
/usr/include/bits/sigcontext.h:28: asm/sigcontext.h: No such file or
directory
make: *** [oroborus.o] Error 1

$ locate sigcontext.h
/usr/include/bits/sigcontext.h
/usr/src/linux-2.2.17/include/asm-i386/sigcontext.h

I made a couple of changes in the Makefile, which didn't help.  This is
its original form.  How can I alter it to point it at sigcontext.h?

Thanks as always, 
Dave.