Grobner



Hoping this has not been hashed to death, i am having problems using the 
Grobner package on maxima, running under sbcl. As soon as maxima runs under
gcl, the grobner package works, but with sbcl, all i get is:

Maxima encountered a Lisp error:

 Error during processing of --eval option "(cl-user::run)":

  The value NIL is not of type PRIORITY-QUEUE.


for example running 
demo("grobner.demo");

I have tried under Ubuntu and FreeBSD both with Maxima 5.10.0 and 5.14.0.
Please, is there any workaround for this problem?


-- 
Michel Talon