Set siteprefix option (meaningful for maatkit for example).

component/perl/buildout.cfg

@@ -17,13 +17,14 @@ recipe = hexagonit.recipe.cmmi
 version = 5.14.1
 url = http://www.cpan.org/src/5.0/perl-${:version}.tar.bz2
 md5sum = 97cd306a2c22929cc141a09568f43bb0
+siteprefix = ${buildout:parts-directory}/site_${:_buildout_section_name_}
 patch-options = -p1
 patches =
   ${perl-keep-linker-flags-in-ldflags.patch:location}/${perl-keep-linker-flags-in-ldflags.patch:filename}
 configure-command =
   sh Configure -des \
     -Dprefix=${buildout:parts-directory}/${:_buildout_section_name_} \
-    -Dsiteprefix=${buildout:parts-directory}/site_${:_buildout_section_name_} \
+    -Dsiteprefix=${:siteprefix} \
     -Dcflags=-I${gdbm:location}/include \
     -Dldflags="-L${gdbm:location}/lib -Wl,-rpath=${gdbm:location}/lib" \
     -Ui_db \