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

Calculating dependencies  ... done!
[ebuild  N     ] net-misc/r8168-8.044.02 

Would you like to merge these packages? [Yes/No] 
>>> Verifying ebuild manifests

>>> Emerging (1 of 1) net-misc/r8168-8.044.02::net-kit
 * r8168-8.044.02.tar.bz2 BLAKE2B SHA512 size ;-) ...                    [ ok ]
 * Determining the location of the kernel source code
 * Found kernel source directory:
 *     /usr/src/linux
 * Found kernel object directory:
 *     /lib/modules/4.14.12-2/build
 * Found sources for kernel version:
 *     4.14.12-2
 * Checking for suitable kernel configuration options...
 *   r8168-8.044.02 requires Realtek 8169 PCI Gigabit Ethernet adapter (CONFIG_R8169) to be DISABLED
 * Please check to make sure these options are set correctly.
 * Failure to do so may cause unexpected problems.
 * Once you have satisfied these options, please try merging
 * this package again.
 * ERROR: net-misc/r8168-8.044.02::net-kit failed (setup phase):
 *   Incorrect kernel configuration options
 * 
 * Call stack:
 *               ebuild.sh, line 121:  Called pkg_setup
 *   r8168-8.044.02.ebuild, line  26:  Called linux-mod_pkg_setup
 *        linux-mod.eclass, line 571:  Called linux-info_pkg_setup
 *       linux-info.eclass, line 921:  Called check_extra_config
 *       linux-info.eclass, line 815:  Called die
 * The specific snippet of code:
 *   		die "Incorrect kernel configuration options"
 * 
 * If you need support, post the output of `emerge --info '=net-misc/r8168-8.044.02::net-kit'`,
 * the complete build log and the output of `emerge -pqv '=net-misc/r8168-8.044.02::net-kit'`.
 * The complete build log is located at '/var/tmp/portage/net-misc/r8168-8.044.02/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/net-misc/r8168-8.044.02/temp/die.env'.
 * Working directory: '/var/tmp/portage/net-misc/r8168-8.044.02/homedir'
 * S: '/var/tmp/portage/net-misc/r8168-8.044.02/work/r8168-8.044.02'

>>> Failed to emerge net-misc/r8168-8.044.02, Log file:

>>>  '/var/tmp/portage/net-misc/r8168-8.044.02/temp/build.log'

 * Messages for package net-misc/r8168-8.044.02:

 *   r8168-8.044.02 requires Realtek 8169 PCI Gigabit Ethernet adapter (CONFIG_R8169) to be DISABLED
 * Please check to make sure these options are set correctly.
 * Failure to do so may cause unexpected problems.
 * Once you have satisfied these options, please try merging
 * this package again.
 * ERROR: net-misc/r8168-8.044.02::net-kit failed (setup phase):
 *   Incorrect kernel configuration options
 * 
 * Call stack:
 *               ebuild.sh, line 121:  Called pkg_setup
 *   r8168-8.044.02.ebuild, line  26:  Called linux-mod_pkg_setup
 *        linux-mod.eclass, line 571:  Called linux-info_pkg_setup
 *       linux-info.eclass, line 921:  Called check_extra_config
 *       linux-info.eclass, line 815:  Called die
 * The specific snippet of code:
 *   		die "Incorrect kernel configuration options"
 * 
 * If you need support, post the output of `emerge --info '=net-misc/r8168-8.044.02::net-kit'`,
 * the complete build log and the output of `emerge -pqv '=net-misc/r8168-8.044.02::net-kit'`.
 * The complete build log is located at '/var/tmp/portage/net-misc/r8168-8.044.02/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/net-misc/r8168-8.044.02/temp/die.env'.
 * Working directory: '/var/tmp/portage/net-misc/r8168-8.044.02/homedir'
 * S: '/var/tmp/portage/net-misc/r8168-8.044.02/work/r8168-8.044.02'