Is this the release 2.20 or checked from git? If the latter, try updating and doing it again, it may have been fixed.
On Fri, Jan 26, 2018 at 12:34 AM Mark H. David mhd@yv.org wrote:
The SLIME inspect feature within SLIME in 2.20 does not work with ACL in our testing on version 10.1 on MacOS with "alisp" images, both SMP and non-SMP. The same SLIME inspect feature does work in the previous version, SLIME 2.19. Finally, there's no known problem with SLIME inspect with any other Lisps that we've tried in either of the versions of SLIME (2.19, 2.20), i.e., with CCL and SBCL.
To recreate, launch SLIME of the appropriate version (2.20) with the appropriate inferior Lisp (ACL alisp 10.1/MacOS), then run slime inspect on any object. For example, do M-x slime-inspect [ret] () [ret]
The above invokes SLIME inspect to inspect the Lisp object nil, entered as (). One could use any Lisp object, e.g., the list '(1 2 3).
So, the above command ought to put you in a SLIME inspect buffer to let you inspect the object. Instead, it throws you into a debugger buffer. Then, in addition, it is particularly onerous because the input prompted for by the debugger is not apparently responded to. For example, typing q to quit or 3 to abort does nothing. You apparently can do nothing but manually kill the emacs buffers involved with Lisp/SLIME.
See an attached screen shot for a picture of how the debugger buffer looks.
The screen shot shows that the debugger is somewhere in no-applicable-method MULTIPROCESSING:PROCESS-PROPERTY-LIST.