To rebuild to the toolchain:

git clone git://git.buildroot.net/buildroot
cd buildroot
git checkout b354417dcef5805adb33cb2e3249d7c7be64cac7

patch -p1 -i <path-to-this-folder>/0001-hermetic-static-build.patch
[... do for all patches in the folder...]

cp <path-to-this-folder>/bruno/Build.Info/defconfig .config

make
(this will bring up menuconfig, just exit and save)
make -j12