- The underlying problem here is that $_ is assumed to contain the path
  to the sourced file, but that isn't true for any version of tcsh I've
  tried... (I guess it must have worked for some version of tcsh?)
  Anyway, that fails and $1 is also empty in the else clause so the
  script fails.

- Reliably finding the path to a sourced file is next to impossible in
  tcsh, so just encourage/force people to pass a path to the script
  directory as an argument.

-- Brad