test -e is not portable enough, so use sufficient test -f

nntpcache/nntpcache.spec

@@ -59,6 +59,7 @@ AutoReqProv:  no
 
 %prep
     %setup -q 
+    %{l_shtool} subst -e 's;test -e;test -f;g' Makefile* */Makefile*
 
 %build
     CC="%{l_cc}" \