avoid changing the OpenPKG sources in place

tomcat/tomcat.spec

@@ -76,10 +76,9 @@ AutoReqProv:  no
 
     #   patch vendor distribution
     (   cd $RPM_BUILD_ROOT%{l_prefix}/libexec/tomcat
-        %{l_rpmtool} subst \
-            's;@l_prefix@;%{l_prefix};g' \
-            -- %{SOURCE tomcat.patch}
-        %{l_prefix}/bin/patch -p0 < %{SOURCE tomcat.patch}
+        cat %{SOURCE tomcat.patch} |\
+        sed -e 's;@l_prefix@;%{l_prefix};g' |\
+        %{l_prefix}/bin/patch -p0
     )
 
     #   make scripts executable