ERROR at //build/config/sysroot.gni:63:7: Assertion failed.
      assert(
      ^-----
Missing sysroot (//build/linux/debian_bullseye_arm64-sysroot). To fix, run: build/linux/sysroot_scripts/install-sysroot.py --arch=arm64
See //build/config/sysroot.gni:64:11: 
          exec_script("//build/dir_exists.py",
          ^--