Milter-greylist

Hello,

I try to build it with:
rpmbuild --define "build_postfix 1" --define "build_user smmsp" -tb milter-greylist-4.2.7.tgz
but it fails:

gcc -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -Wall -DUSE_POSTFIX -D_BSD_SOURCE -I. -I.    -c -o macro.o macro.c
bison -y -p`echo conf_yacc.c|sed 's/^\([^_]\{1,\}_\).*$/\1/'` conf_yacc.y
flex -oconf_lex.c conf_lex.l
bison -y -p`echo dump_yacc.c|sed 's/^\([^_]\{1,\}_\).*$/\1/'` dump_yacc.y
mv y.tab.c dump_yacc.c
flex -odump_lex.c dump_lex.l
gcc -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -Wall -DUSE_POSTFIX -D_BSD_SOURCE -I. -I.    -c -o conf.o conf.c
mv y.tab.c conf_yacc.c
mv: nepavyksta patikrinti \u201ey.tab.c\u201c: No such file or directory

I think it uses make -j2, and 2nd bison overwrites the 1st bison's output (y.tab.c).
It builds if I remove %{?_smp_mflags} from the spec file:

--- milter-greylist.spec.orig	2012-03-28 03:30:25.000000000 +0300
+++ milter-greylist.spec	2012-03-28 03:41:28.000000000 +0300
@@ -109,7 +109,7 @@
 	--with-libGeoIP \
 %endif
 
-%{__make} %{?_smp_mflags}
+%{__make}
 
 
 %install


Does anyone know how to deal with such situations "oficially"? Or is it OK to just remove %{?_smp_mflags}?

Regards,
Nerijus