>>> Emerging : portage://sys-power/apcupsd-3.14.14-r4:run?{[]}

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

Calculating dependencies... done!

 └─step  1─┤ useflag portage://sys-apps/util-linux-2.42.3 (tty-helpers)

 └─step  2─┤ download  portage://dev-libs/libusb-1.0.30
             │           └─ file ─┤ 640.73 Kb  	 libusb-1.0.30.tar.bz2
             │ download  portage://dev-libs/libusb-compat-0.1.9
             │           └─ file ─┤ 321.19 Kb  	 libusb-compat-0.1.9.tar.bz2
             │ download  portage://net-mail/mailutils-3.21
             │           └─ file ─┤ 3.22 Mb  	 mailutils-3.21.tar.xz
             │ download  portage://sys-apps/util-linux-2.42.3
             │           └─ file ─┤ 10.22 Mb  	 util-linux-2.42.3.tar.xz
             │ download  portage://sys-power/apcupsd-3.14.14-r4
             │           └─ file ─┤ 1.76 Mb  	 apcupsd-3.14.14.tar.gz

Total: 6 actions (1 useflag, 5 downloads), grouped into 2 steps.
       16.14 Mb to be downloaded.



>>> Assumptions taken during proving & planning:

  USE flag change (1 package):
  Add to /etc/portage/package.use:
    sys-apps/util-linux tty-helpers


>>> Blockers added during proving & planning:

  [blocks B] !>=sys-apps/shadow-4.7-r2 (soft blocker, phase: run, required by: portage://sys-apps/util-linux-2.42.3)


Error The proof for your build plan contains domain assumptions. Please verify:


>>> Domain assumptions

- Other: 
  unreachable(portage://virtual/libusb-0-r2:install,grouped_package_dependency(no,dev-libs,libusb-compat,[package_dependency(run,no,dev-libs,libusb-compat,greaterequal,version([0,1,5],,4,0,[],2,0.1.5-r2),[],[use(optenable(abi_x86_32),negative),use(optenable(abi_x86_64),negative),use(optenable(abi_x86_x32),negative),use(optenable(abi_mips_n32),negative),use(optenable(abi_mips_n64),negative),use(optenable(abi_mips_o32),negative),use(optenable(abi_s390_32),negative),use(optenable(abi_s390_64),negative)])]):run)