* Determining the location of the kernel source code
 * Found kernel source directory:
 *     /usr/src/linux
 * Could not find a usable .config in the kernel source directory.
 * Please ensure that /usr/src/linux points to a configured set of Linux sources.
 * If you are using KBUILD_OUTPUT, please set the environment var so that
 * it points to the necessary object directory so that it might find .config.

!!! ERROR: x11-drivers/ati-drivers-8.25.18 failed.
Call stack:
  ebuild.sh, line 1555:   Called dyn_setup
  ebuild.sh, line 668:   Called pkg_setup
  ati-drivers-8.25.18.ebuild, line 69:   Called linux-mod_pkg_setup
  linux-mod.eclass, line 465:   Called linux-info_pkg_setup
  linux-info.eclass, line 549:   Called die

!!! Unable to calculate Linux Kernel version
!!! If you need support, post the topmost build error, and the call stack if relevant.

!!! This ebuild is from an overlay: '/usr/local/overlays/vlos'