/usr/lib/rpm/redhat/find-requires in redhat-rpm-config-8.0.45-6 has

if [ "$1" ]
then
   package_name = "$1"
fi

It leads to

/usr/lib/rpm/redhat/find-requires: line 10: package_name: command not found
Finding  Requires: /usr/lib/rpm/redhat/find-requires kernel

when building noarch kernel rpm. This change

d[hjl@gnu-2 kernel-FC5]$ diff -up /tmp/find-requires
/usr/lib/rpm/redhat/find-reuires
--- /tmp/find-requires  2006-11-06 10:27:50.000000000 -0800
+++ /usr/lib/rpm/redhat/find-requires   2006-11-06 10:27:58.000000000 -0800
@@ -7,7 +7,7 @@
 
 if [ "$1" ]
 then
-   package_name = "$1"
+   package_name="$1"
 fi
 
 ulimit -c 0

works for me.