cups-1.1.20-5.1.src.rpm
A patch (cups-pie.patch) that adds -pie to LDFLAGS have a short
mistype; instead of adding -pie to LDFLAGS in filter/Makefile it sets
LDFLAGS to -pie, thus throwing away previous LDFLAGS value taken from
../Makedefs.

That makes -L../cups disappear from LDFLAGS and leads to the following
error while rebuilding cups from src.rpm:

Linking hpgltops...
gcc -pie -o hpgltops hpgl-attr.opie hpgl-config.opie hpgl-main.opie
hpgl-prolog.opie hpgl-char.opie hpgl-input.opie hpgl-polygon.opie
hpgl-vector.opie common.o -lcups -lnsl -lcrypt   -lm
/usr/bin/ld: cannot find -lcups
collect2: ld returned 1 exit status

Probably it builds on your build system where previous version of cups
 packages are installed, so you haven't noticed the bug.

This is actual part of cups-pie.patch with error:

--- cups-1.1.20/filter/Makefile.pie     2003-11-17 22:04:53.000000000
+0000
+++ cups-1.1.20/filter/Makefile 2004-02-05 12:42:53.000000000 +0000
@@ -25,6 +25,7 @@
 #
                                                                     
          
 include ../Makedefs
+LDFLAGS = -pie