circular structures and bin files

[Scott McKay <SWM@sapsucker.scrc.symbolics.com>]

    Date: 22 Dec 87 14:08:50 EST
    From: Timothy Daly <DALY@ibm.com>

    Symbolics cannot handle the following in a compile-file.

    (defun foo () '#1=(#1#))

    This will fail complaining that bin files cannot handle
    circular objects. We create circular objects all over the
    place in our data structures and need to write them out.
    Symbolics customer service recommends that we un-circularize
    the objects first. Ha.

    Does anyone have a fix for this behavior?

Don't dump the objects themselves.  Write a fasd-form method for the
object types in question which which knows how to reconstruct the object
at load time.

While this restriction has not been documented (it will be in 7.2), it
has been present and "well known" for a very long time.