[cctbxbb] building cctbx with external boost

Hi I vaguely remember a discussion some time ago about building cctbx with stand-alone boost libraries. Do you know what boost versions are compatible? Is using the --scan-boost option enough? I see that Gentoo has extra patch to unbundle boost from cctbx: http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/sci-libs/cctbx/files... Is it necessary? I'm asking because at this moment we have in CCP4 two versions of boost, one in cctbx and the other for building DSSP (it uses different subset of boost libs than cctbx). It would make sense to use a single version for both, if possible. Cheers Marcin