Ok, I tried it again with :debug 0 as you suggested and the result is the same:
(asdf:oos 'asdf:load-source-op :ltk)
; loading system definition from /lisp/lib/ltk-0.91/ltk.asd into ; #<ASDF0 package> ;;; Loading "/lisp/lib/ltk-0.91/ltk.asd" ; registering #<SYSTEM LTK 15100376> as LTK ;;; Loading "c:/lisp/lib/ltk-0.91/ltk.lisp" NIL
(setf ltk:*wish-pathname* "c:/Tcl/bin/wish85.exe")
"c:/Tcl/bin/wish85.exe"
;(setf ltk:*debug-tk* t)
(ltk:ltktest)
#<two-way stream 00f0db68> An error of type SIMPLE-ERROR has occured: Read or write operation to stream #<output stream ""c:/Tcl/bin/wish85.exe" "-name" "LTK""> signaled an error. Explanation: Invalid argument. Read or write operation to stream #<output stream ""c:/Tcl/bin/wish85.exe" "-name" "LTK""> signaled an error. Explanation: Invalid argument. Broken at SI:BYTECODES.No restarts available. Broken at LTK:SEND-WISH. File: #P"c:/lisp/lib/ltk-0.91/ltk.lisp" (Form #22)
:B
Backtrace: LTK:SEND-WISH > ltk::init-wish > lambda > lambda > ltk::use-debugger > ltk::use-trivial-debugger > lambda > l tk:start-wish > ltk:start-wish > ltk:call-with-ltk > ltk:ltktest > si:bytecodes > si:bytecodes > si:bytecodes