No toolchain specified in board overlay or on command line

In following the Quick Guide, in the build stage, I enter and
execute cros_sdk. It goes for quite some time, then spits out this error. I
executed *cros_sdk* --*delete* and tried it again...same series of errors.
Any help would be appreciated.

cros_sdk -- ./build_packages --board=${amd64-generic}

Error received:

ERROR : No toolchain specified in board overlay or on command line.
ERROR : script called: ./build_packages '--board=generic'
ERROR : Backtrace: (most recent call is last)
ERROR : file build_packages, line 142, called: die_err_trap
'"${SCRIPTS_DIR}"/setup_board --quiet --board=${FLAGS_board}
"${UPDATE_ARGS[@]}"' '1'
ERROR :
ERROR : Command failed:
ERROR : Command '"${SCRIPTS_DIR}"/setup_board --quiet
--board=${FLAGS_board} "${UPDATE_ARGS[@]}"' exited with nonzero code: 1
ERROR : (Note bash sometimes misreports "command not found" as exit
code 1 instead of 127)