These are the actions I will take, in order:

u   sys-kernel/linux-headers:0::arbor 4.10 to ::installed replacing 4.0
    build_options: symbols=split jobs=2 -dwarf_compress (-recommended_tests) -trace work=tidyup
    Reasons: target (system) (system::arbor), net-misc/openssh-7.5_p1-r1:0::installed, sys-apps/iproute2-4.10.0-r1:0::arbor, 5 more

u   sys-apps/iproute2:0::arbor 4.10.0-r1 to ::installed replacing 4.0.0-r1
    -atm -berkdb PROVIDERS: elfutils+ -libelf+ build_options: symbols=split jobs=2 -dwarf_compress recommended_tests -trace work=tidyup
    Reasons: sys-boot/dracut-045:0::installed (sug)

Total: 2 upgrades

providers:
    elfutils:                      Use elfutils as the libelf provider
    libelf:                        Use libelf as the libelf provider

Executing pretend actions: 1 of 2]2;1 of 2 pretend sys-kernel/linux-headers-4.10:0::arbor
linux-headers-4.10>  * Kernel headers version mismatch: Installing kernel headers newer than the
linux-headers-4.10>  * running kernel can break your system. Do not proceed unless you know what
linux-headers-4.10>  * you're doing.

]2;Completed 1 of 2 pretend sys-kernel/linux-headers-4.10:0::arbor2 of 2]2;2 of 2 pretend sys-apps/iproute2-4.10.0-r1:0::arbor]2;Completed 2 of 2 pretend sys-apps/iproute2-4.10.0-r1:0::arbor

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