Followup to <c288dfb0f33ef4a713680190b5b2e2ca69cfb171>:
    - Disable linking bash and coreutils statically until the necessary
      fixes to psxstub and psxscl have been committed upstream.
    
    Replace non-portable `tar -axf' invokations with {bunzip2,gunzip,xz} -d
    | tar -xf - depending on the ${PKG_FNAME} file extension.