Commit 161f0861de512991a879a50b2868c503f4715352 forgot to update a couple of spots in the new virtx function, namely: debug-print "${FUNCNAME}: ${VIRTUALX_COMMAND} \"$@\"" and the die message: [[ ${retval} -ne 0 ]] && die "${FUNCNAME}: the ${VIRTUALX_COMMAND} failed." VIRTUALX_COMMAND is not used by virtx(), the command is "$@".
https://github.com/gentoo/gentoo/pull/532
commit 59e0cdef8d97610eda3ea3f28bdf562376a828a0 Author: Davide Pesavento <davidepesa@gmail.com> Date: Sun Dec 27 01:04:28 2015 +0100 virtualx.eclass: fix diagnostic messages in virtx() Gentoo-Bug: 569876