localhost escobar # emerge --update --deep --newuse world
Calculating world dependencies... done!
>>> Verifying ebuild Manifests...

>>> Emerging (1 of 21) sys-fs/cryptsetup-luks-1.0.4-r3 to /
 * cryptsetup-luks-1.0.4.tar.bz2 RMD160 ;-) ...                           [ ok ]
 * cryptsetup-luks-1.0.4.tar.bz2 SHA1 ;-) ...                             [ ok ]
 * cryptsetup-luks-1.0.4.tar.bz2 SHA256 ;-) ...                           [ ok ]
 * cryptsetup-luks-1.0.4.tar.bz2 size ;-) ...                             [ ok ]
 * checking ebuild checksums ;-) ...                                      [ ok ]
 * checking auxfile checksums ;-) ...                                     [ ok ]
 * checking miscfile checksums ;-) ...                                    [ ok ]
 * checking cryptsetup-luks-1.0.4.tar.bz2 ;-) ...                         [ ok ]
 * 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: sys-fs/cryptsetup-luks-1.0.4-r3 failed.
Call stack:
  ebuild.sh, line 1637:   Called dyn_setup
  ebuild.sh, line 704:   Called qa_call 'pkg_setup'
  ebuild.sh, line 44:   Called pkg_setup
  cryptsetup-luks-1.0.4-r3.ebuild, line 47:   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.
!!! A complete build log is located at '/var/tmp/portage/sys-fs/cryptsetup-luks-1.0.4-r3/temp/build.log'.

localhost escobar #