why use docker env. to build banana pi source code 1. allwinner tools needs ubuntu12.04 with ia32-libs ... 2. user maybe use ubuntu 12.04 or 14.04 and newer like 16.04, the docker env. the same, even other linux like fedora opensuse archlinux ...., or other os like macos , windows ... 3. build BPI-Mx-bsp env. than mainline kernel & uboot or android 4.X or android 5.X / 6.X not the same.