In the REPL buffer I entered the (ROOM) command:

CL-USER> (room) Dynamic space usage is: 1,337,928,544 bytes. Read-only space usage is: 1,872 bytes. Static space usage is: 1,128 bytes. Control stack usage is: 3,008 bytes. Binding stack usage is: 576 bytes. Garbage collection is currently enabled.

In SLDB buffer:

The value 804013168 is not of type FIXNUM. [Condition of type TYPE-ERROR]

Restarts: 0: [ABORT-REQUEST] Abort handling SLIME request. 1: [ABORT] Exit debugger, returning to top level.

Backtrace: 0: ((LAMBDA (SB-VM::OBJ TYPE SB-VM::SIZE)) #<unavailable argument> #<unavailable argument> #<unavailable argument>) 1: (SB-VM::MAP-ALLOCATED-OBJECTS #<unavailable argument> #<unavailable argument>) 2: (SB-VM::TYPE-BREAKDOWN :DYNAMIC) 3: (SB-VM:MEMORY-USAGE) 4: (ROOM :DEFAULT) 5: (SB-INT:SIMPLE-EVAL-IN-LEXENV (ROOM) #<NULL-LEXENV>) 6: (SWANK::EVAL-REGION "(room) " T) 7: ((LAMBDA ())) 8: ((LAMBDA (SWANK-BACKEND::FN)) #<CLOSURE (LAMBDA #) {11C3DFB5}>) 9: (SWANK::CALL-WITH-BUFFER-SYNTAX #<CLOSURE (LAMBDA #) {11C3DFB5}>) 10: (SB-INT:SIMPLE-EVAL-IN-LEXENV (SWANK:LISTENER-EVAL "(room) ") #<NULL-LEXENV>) 11: ((LAMBDA ())) 12: ((LAMBDA (SWANK-BACKEND::HOOK SWANK-BACKEND::FUN)) #<FUNCTION SWANK:SWANK-DEBUGGER-HOOK> #<CLOSURE (LAMBDA #) {11C3D8DD}>) 13: ((LAMBDA ())) 14: ((LAMBDA (SWANK-BACKEND::HOOK SWANK-BACKEND::FUN)) #<FUNCTION SWANK:SWANK-DEBUGGER-HOOK> #<FUNCTION (LAMBDA #) {11822205}>) 15: (SWANK::CALL-WITH-REDIRECTED-IO #<SWANK::CONNECTION {1181E8C9}> #<CLOSURE (LAMBDA #) {11C3B2ED}>) 16: (SWANK::CALL-WITH-CONNECTION #<SWANK::CONNECTION {1181E8C9}> #<FUNCTION (LAMBDA #) {11822205}>) 17: (SWANK::HANDLE-REQUEST #<SWANK::CONNECTION {1181E8C9}>) 18: (SWANK::PROCESS-AVAILABLE-INPUT #<SB-SYS:FD-STREAM for "a constant string" {1181F1B1}> #<CLOSURE (LAMBDA #) {11C3B2D5}>) 19: ((FLET SWANK::HANDLER)) 20: ((LAMBDA (SWANK-BACKEND::_)) #<unused argument>) 21: (SB-IMPL::SUB-SERVE-EVENT NIL 0) 22: (SB-SYS:WAIT-UNTIL-FD-USABLE 0 :INPUT NIL) 23: (SB-IMPL::REFILL-BUFFER/FD #<SB-SYS:FD-STREAM for "standard input" {1181E211}>) 24: (SB-IMPL::INPUT-CHAR/UTF-8 #<SB-SYS:FD-STREAM for "standard input" {1181E211}> NIL #:EOF-OBJECT) 25: (READ-CHAR #<SB-SYS:FD-STREAM for "standard input" {1181E211}> NIL #:EOF-OBJECT #<unused argument>) 26: (READ-CHAR #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {1000A1B1}> NIL #:EOF-OBJECT #<unused argument>) 27: (READ-PRESERVING-WHITESPACE #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {1000A1B1}> NIL (NIL) T) 28: (READ-PRESERVING-WHITESPACE #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {1000A1B1}> NIL (NIL) NIL) 29: (READ #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {1000A1B1}> NIL (NIL) NIL) 30: (SB-IMPL::REPL-READ-FORM-FUN #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {1000A1B1}> #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDOUT* {10009BD9}>) 31: (SB-IMPL::REPL-FUN NIL) 32: ((LAMBDA ())) 33: ((LAMBDA ())) 34: (SB-IMPL::%WITH-REBOUND-IO-SYNTAX #<CLOSURE (LAMBDA #) {1181E0C5}>) 35: (SB-IMPL::TOPLEVEL-REPL NIL) 36: (SB-IMPL::TOPLEVEL-INIT) 37: ((LABELS SB-IMPL::RESTART-LISP))

SBCL 1.0.1 OS X PPC with SLIME 2006-12-24