touch: setting times of `/var/tmp/portage/gentoo-sources-2.6.17-r8/.unpacked': Function not implemented

!!! ERROR: sys-kernel/gentoo-sources-2.6.17-r8 failed.
Call stack:
  ebuild.sh, line 1539:   Called dyn_unpack
  ebuild.sh, line 712:   Called die

!!! IO Failure -- Failed 'touch .unpacked' in /var/tmp/portage/gentoo-sources-2.6.17-r8
!!! If you need support, post the topmost build error, and the call stack if relevant.