[Libguestfs] how do i use a blob appliance the compiling from source

Hi, Since I've never succeeded to compile libguestfs from source on Gentoosince the build process of the appliance based on debootstrap fails, I'm wondering how can I tell the compilation process to use a precompiled blob appliance? Also can I use non fedora & debian but use some minimal gentoo based appliance I have? Thanks Alex