No guys, seriously, boost no, please.
Created attachment 177198 [details, diff] Patch that modifies the build system to use the system boost. The attached patch modifies the build system to use the system boost. It needs to be applied after the 2.0.1-gentoo.patch since that also mucks about with Rakefile. Unfortunately passenger does not build with boost-1.34. The bundled copy seems to be 1.35, so perhaps upgrading does work, but I don't have time right now to test that.
this patch needs to be updated for passenger 2.2.5. it seems boost is not built with passenger nowadays although it is still bundled in the tarball. they just seem to build their oxt extension for boost. (http://groups.google.com/group/phusion-passenger/browse_thread/thread/e3edf9a313385089)
as Benedikt Böhm already pointed out, passenger no longer bundles boost, so please close this rather ancient bug.