To make the `extern' package (rooted under the local package) you must:

    1)	add the package references to the file local$lib/extern.pkg

    2)	% setenv extern 'local$extern/'

prior to doing a `mkpkg -p extern'.  The unix environment definition
can be added to the file local$SOURCEME which can be sourced to define
all the local external packages for software development.

All other behavior (for an external package) should be normal.
