# emerge nvidia-kernel nvidia-glx
Calculating dependencies... done!
>>> starting parallel fetching
>>> Emerging (1 of 2) media-video/nvidia-kernel-1.0.8762-r1 to /
>>> Downloading http://distfiles.gentoo.org/distfiles/NVIDIA-Linux-x86-1.0-8762-pkg1.run
--21:07:17--  http://distfiles.gentoo.org/distfiles/NVIDIA-Linux-x86-1.0-8762-pkg1.run
           => `/usr/portage/distfiles/NVIDIA-Linux-x86-1.0-8762-pkg1.run'
Resolving distfiles.gentoo.org... 216.165.129.135, 156.56.247.195, 64.50.236.52, ...
Connecting to distfiles.gentoo.org|216.165.129.135|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 13,032,175 (12M) [text/plain]

100%[====================================>] 13,032,175   175.29K/s    ETA 00:00

21:08:29 (176.11 KB/s) - `/usr/portage/distfiles/NVIDIA-Linux-x86-1.0-8762-pkg1.run' saved [13032175/13032175]

>>> checking ebuild checksums ;-)
>>> checking auxfile checksums ;-)
>>> checking miscfile checksums ;-)
>>> checking NVIDIA-Linux-x86-1.0-8762-pkg1.run ;-)
 * Determining the location of the kernel source code
 * Unable to find kernel sources at /usr/src/linux
 * This package requires Linux sources.
 * Please make sure that /usr/src/linux points at your running kernel,
 * (or the kernel you wish to build against).
 * Alternatively, set the KERNEL_DIR environment variable to the kernel sources location

!!! ERROR: media-video/nvidia-kernel-1.0.8762-r1 failed.
Call stack:
  ebuild.sh, line 1555:   Called dyn_setup
  ebuild.sh, line 668:   Called pkg_setup
  nvidia-kernel-1.0.8762-r1.ebuild, line 58:   Called linux-mod_pkg_setup
  linux-mod.eclass, line 419:   Called linux-info_pkg_setup
  linux-info.eclass, line 554:   Called die

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