Knoppix / # emerge -u xorg-x11
Calculating dependencies... done!
>>> starting parallel fetching

>>> Emerging (1 of 98) x11-libs/libXmu-1.0.2 to /
>>> checking ebuild checksums ;-)
>>> checking auxfile checksums ;-)
>>> checking miscfile checksums ;-)
>>> Unpacking source...

!!! ERROR: x11-libs/libXmu-1.0.2 failed.
Call stack:
  ebuild.sh, line 1545:   Called dyn_unpack
  ebuild.sh, line 711:   Called src_unpack
  ebuild.sh, line 1254:   Called x-modular_src_unpack
  x-modular.eclass, line 266:   Called x-modular_unpack_source
  x-modular.eclass, line 208:   Called unpack
  ebuild.sh, line 355:   Called die

!!! Nothing passed to the 'unpack' command
!!! If you need support, post the topmost build error, and the call stack if relevant.

Error in sys.exitfunc: