CL-USER(25): (defclass c (d) ((q :initarg :q))) #<STANDARD-CLASS C {B5BEE0}>
CL-USER(26): (make-instance 'c :q t) Debugger invoked on condition of type PROGRAM-ERROR: Invalid initarg :Q.
The error should say instead something about d not being defined.
This in build of a freshly updated trunk abcl
-Alan