In current CVS on CLISP, xref-results (function the CLISP backend uses for who-calls results) doesn't work, because it calls fspec-source-locations which was removed by Helmut on March 10.
Helmut, could you take a look at xref-results in swank-clisp and see if it can be converted easily to the new code? I don't immediately understand how that section works, so if you can fix it easily, it would be great.