$ sudo emerge \>=zen-sources-9999

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

Calculating dependencies... done!
[ebuild  NS   *] sys-kernel/zen-sources-9999::mva [2.6.38_p20110510::gentoo] USE="minimal -build -symlink" 0 kB

Total: 1 package (1 in new slot), Size of downloads: 0 kB

Would you like to merge these packages? [Yes/No] y

>>> Verifying ebuild manifests

>>> Emerging (1 of 1) sys-kernel/zen-sources-9999 from mva
>>> cfg-update-1.8.2-r1: Creating checksum index...
 * Be carefull!! You are about to install live kernel sources.
 * Git zen-sources are extremely unsupported, even from the upstream
 * developers. Use them at your own risk and don't bite us if your
 * system explodes
>>> Preparing to unpack ...
>>> Unpacking source...
Cloning into bare repository /mnt/terahome/store/portage-distfiles/egit-src/zen-stable...
remote: Counting objects: 88964, done.
remote: Compressing objects: 100% (66335/66335), done.
remote: Total 88964 (delta 46159), reused 49829 (delta 21596)
Receiving objects: 100% (88964/88964), 136.92 MiB | 346 KiB/s, done.
Resolving deltas: 100% (46159/46159), done.
GIT NEW clone -->
   repository:               git://zen-kernel.org/kernel/zen-stable.git
   at the commit:            81ee382bff65ceba3aaadba91600016f75347cce
   branch:                   master
   storage directory:        "/mnt/terahome/store/portage-distfiles/egit-src/zen-stable"
   checkout type:            bare repository
Cloning into /home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/work/linux-3.99-zen0...
fatal: attempt to fetch/clone from a shallow repository
fatal: The remote end hung up unexpectedly
 * ERROR: sys-kernel/zen-sources-9999 failed (unpack phase):
 *   git-2_move_source: sync to "/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/work/linux-3.99-zen0" failed
 *
 * Call stack:
 *     ebuild.sh, line   85:  Called src_unpack
 *   environment, line 2922:  Called git-2_src_unpack
 *   environment, line 1959:  Called git-2_move_source
 *   environment, line 1910:  Called die
 * The specific snippet of code:
 *       ${MOVE_COMMAND} "${EGIT_SOURCEDIR}" || die "${FUNCNAME}: sync to \"${EGIT_SOURCEDIR}\" failed";
 *
 * If you need support, post the output of 'emerge --info =sys-kernel/zen-sources-9999',
 * the complete build log and the output of 'emerge -pqv =sys-kernel/zen-sources-9999'.
 * This ebuild is from an overlay named 'mva': '/var/lib/layman/mva/'
 * The complete build log is located at '/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/temp/build.log'.
 * The ebuild environment file is located at '/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/temp/environment'.
 * S: '/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/work/linux-3.99-zen0'

>>> Failed to emerge sys-kernel/zen-sources-9999, Log file:

>>>  '/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/temp/build.log'

 * Messages for package sys-kernel/zen-sources-9999:

 * Be carefull!! You are about to install live kernel sources.
 * Git zen-sources are extremely unsupported, even from the upstream
 * developers. Use them at your own risk and don't bite us if your
 * system explodes
 * ERROR: sys-kernel/zen-sources-9999 failed (unpack phase):
 *   git-2_move_source: sync to "/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/work/linux-3.99-zen0" failed
 *
 * Call stack:
 *     ebuild.sh, line   85:  Called src_unpack
 *   environment, line 2922:  Called git-2_src_unpack
 *   environment, line 1959:  Called git-2_move_source
 *   environment, line 1910:  Called die
 * The specific snippet of code:
 *       ${MOVE_COMMAND} "${EGIT_SOURCEDIR}" || die "${FUNCNAME}: sync to \"${EGIT_SOURCEDIR}\" failed";
 *
 * If you need support, post the output of 'emerge --info =sys-kernel/zen-sources-9999',
 * the complete build log and the output of 'emerge -pqv =sys-kernel/zen-sources-9999'.
 * This ebuild is from an overlay named 'mva': '/var/lib/layman/mva/'
 * The complete build log is located at '/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/temp/build.log'.
 * The ebuild environment file is located at '/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/temp/environment'.
 * S: '/home/somebody/portage-tmp/portage/sys-kernel/zen-sources-9999/work/linux-3.99-zen0'