app-admin/eselect uses ROOT environmental variable. Support for --root="${ROOT}" command-line option was added: https://gitweb.gentoo.org/proj/eselect.git/commit/?id=285b2c59ed8234d1480012ca3020cbd4368a9d16 https://gitweb.gentoo.org/proj/eselect.git/commit/?id=62501cdddf09cd92689fb5e8f87c4369fd636cf5 For convenience, eselect.eclass can be created: IDEPEND=">=app-admin/eselect-1.4.19" eselect() { command eselect --root="${ROOT}" "${@}" }
The --root option is available in eselect-1.4.20 which is stable on all archs.