Apply by doing:
	cd /usr/src
	patch -p0 < 013_syspipe.patch
And then rebuild your kernel.

Index: sys/kern/uipc_syscalls.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_syscalls.c,v
retrieving revision 1.42
diff -u -r1.42 uipc_syscalls.c
--- sys/kern/uipc_syscalls.c	20 Sep 2001 17:02:31 -0000	1.42
+++ sys/kern/uipc_syscalls.c	5 Feb 2002 19:20:55 -0000
@@ -863,10 +863,7 @@
 }
 
 int
-sys_pipe(p, v, retval)
-	struct proc *p;
-	void *v;
-	register_t *retval;
+sys_pipe(struct proc *p, void *v, register_t *retval)
 {
 	register struct sys_pipe_args /* {
 		syscallarg(int *) fdp;
@@ -882,8 +879,8 @@
 	error = copyout((caddr_t)fds, (caddr_t)SCARG(uap, fdp),
 	    2 * sizeof (int));
 	if (error) {
-		fdrelease(p, retval[0]);
-		fdrelease(p, retval[1]);
+		fdrelease(p, fds[0]);
+		fdrelease(p, fds[1]);
 	}
 	return (error);
 }