Steps to repro:

1. Enter Chrome OS chroot
2. ./setup_board --board=betty --force
3. ./build_packages --board=betty

Expected: Binary packages are used
Actual: Binary packages are not used except for chromeos-base/chromeos-chrome


The problem goes away by running this command instead:

 ./build_packages --board=betty --nowithrevdeps

IIUC, reverse deps logic enforces all packages to be built from source. I'm not familiar with the logic but I believe there is something wrong.