+341: PPRINT-LOGICAL-BLOCK / PPRINT-FILL / PPRINT-LINEAR sharing detection.
+ (from Paul Dietz' test suite)
+
+ CLHS on PPRINT-LINEAR and PPRINT-FILL (and PPRINT-TABULAR, though
+ that's slightly different) states that these functions perform
+ circular and shared structure detection on their object. Therefore,
+
+ a.(let ((*print-circle* t))
+ (pprint-linear *standard-output* (let ((x '(a))) (list x x))))
+ should print "(#1=(A) #1#)"
+
+ b.(let ((*print-circle* t))
+ (pprint-linear *standard-output*
+ (let ((x (cons nil nil))) (setf (cdr x) x) x)))
+ should print "#1=(NIL . #1#)"
+
+ (it is likely that the fault lies in PPRINT-LOGICAL-BLOCK, as
+ suggested by the suggested implementation of PPRINT-TABULAR)
+
+342: PPRINT-TABULAR / PPRINT-LOGICAL-BLOCK logical block start position
+ The logical block introduced by PPRINT-LOGICAL-BLOCK should not
+ include the prefix, so that
+ (pprint-tabular *standard-output* '(1 2 3) t nil 2)
+ should print
+ "(1 2 3)" rather than "(1 2 3)".
+
+343: MOP:COMPUTE-DISCRIMINATING-FUNCTION overriding causes error
+ Even the simplest possible overriding of
+ COMPUTE-DISCRIMINATING-FUNCTION, suggested in the PCL implementation
+ as "canonical", does not work:
+ (defclass my-generic-function (standard-generic-function) ()
+ (:metaclass funcallable-standard-class))
+ (defmethod compute-discriminating-function ((gf my-generic-function))
+ (let ((dfun (call-next-method)))
+ (lambda (&rest args)
+ (apply dfun args))))
+ (defgeneric foo (x)
+ (:generic-function-class my-generic-function))
+ (defmethod foo (x) (+ x x))
+ (foo 5)
+ signals an error. This error is the same even if the LAMBDA is
+ replaced by (FUNCTION (SB-KERNEL:INSTANCE-LAMBDA ...)). Maybe the
+ SET-FUNCALLABLE-INSTANCE-FUN scary stuff in
+ src/code/target-defstruct.lisp is broken? This seems to be broken
+ in CMUCL 18e, so it's not caused by a recent change.
+
+344: more (?) ROOM T problems (possibly part of bug 108)
+ In sbcl-0.8.12.51, and off and on leading up to it, the
+ SB!VM:MEMORY-USAGE operations in ROOM T caused
+ unhandled condition (of type SB-INT:BUG):
+ failed AVER: "(SAP= CURRENT END)"
+ Several clever people have taken a shot at this without fixing
+ it; this time around (before sbcl-0.8.13 release) I (WHN) just
+ commented out the SB!VM:MEMORY-USAGE calls until someone figures
+ out how to make them work reliably with the rest of the GC.
+
+ (Note: there's at least one dubious thing in room.lisp: see the
+ comment in VALID-OBJ)
+
+345: backtrace on x86 undefined function
+ In sbcl-0.8.13 (and probably earlier versions), code of the form
+ (flet ((test () (#:undefined-fun 42)))
+ (funcall #'test))
+ yields the debugger with a poorly-functioning backtrace. Brian
+ Downing fixed most of the problems on non-x86 architectures, but on
+ the x86 the backtrace from this evaluation does not reveal anything
+ about the problem. (See tests in debug.impure.lisp)
+
+346: alpha backtrace
+ In sbcl-0.8.13, all backtraces from errors caused by internal errors
+ on the alpha seem to have a "bogus stack frame".
+
+347: FUNCALL forms and compiler-macros
+ (reported by Johan Bockgård on #lisp)
+ The example
+ (funcall (compiler-macro-function 'square) '(funcall #'square x) nil)
+ => (EXPT X 2)
+ from CLHS entry for DEFINE-COMPILER-MACRO fails in 0.8.13.41 with an
+ error. Fixed in CMUCL 19a.