These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.74 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/libusb-1.0.30:1::gentoo  USE="-debug -doc -examples -static-libs -test -udev -verify-sig" 641 KiB
[ebuild  N     ] virtual/libusb-1-r2:1::gentoo  USE="-udev" 0 KiB
[ebuild     U  ] sys-apps/util-linux-2.42.3::gentoo [2.41.3::gentoo] USE="cramfs hardlink logger ncurses nls pam python readline su suid tty-helpers* (unicode) -audit -build -caps -cryptsetup -fdformat -kill -magic (-rtas) (-selinux) -slang -static-libs (-systemd) -test -udev -uuidd -verify-sig" PYTHON_TARGETS="python3_14* -python3_12 -python3_13* (-python3_11%)" 10466 KiB
[ebuild  N     ] dev-libs/libusb-compat-0.1.9::gentoo  USE="(split-usr) -debug -examples" 322 KiB
[ebuild  N     ] net-mail/mailutils-3.21::gentoo  USE="clients gdbm nls pam python (split-usr) ssl threads -berkdb -bidi -emacs -guile -kerberos -kyotocabinet -ldap -mysql -postgres -sasl -servers -static-libs -tcpd -test -tokyocabinet" GUILE_SINGLE_TARGET="3-0 -2-2" PYTHON_SINGLE_TARGET="python3_14 -python3_12 -python3_13" 3302 KiB
[ebuild  N     ] virtual/libusb-0-r2::gentoo  0 KiB
[ebuild  N     ] virtual/mailx-4::gentoo  0 KiB
[ebuild  N     ] sys-power/apcupsd-3.14.14-r4::gentoo  USE="modbus usb -cgi (-selinux) -snmp" 1801 KiB

Total: 8 packages (1 upgrade, 7 new), Size of downloads: 16530 KiB

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by sys-power/apcupsd-3.14.14-r4::gentoo
# required by =sys-power/apcupsd-3.14.14-r4 (argument)
>=sys-apps/util-linux-2.42.3 tty-helpers