BUG (1.8): can't redefine /debug/

[Michael Tiedtke]

As the bug database doesn't allow filing bugs even when you have a Savannah account I'm sending this to the mailing list.
 (Errore: Azione Non Disponibile: L'Appartenenza al Progetto è richiesta per inserire elementi in questo gestore.)

I never got used to that second REPL (usually of the hosting system) which they called debug. My own debug procedure produces simple debug messages and it is defined in my "pretext.scm". But when I want to override the core binding I only get strange error messages in Guile 1.8.

With this header in the module:

(define-module (pretext)
  #:replace (list-head debug))

it tells me something about a mutex when I try to load it:

address@hidden:~/Desktop/viper$ guile
guile> (use-modules (pretext))
ERROR: mutex already locked by current thread
ABORT: (misc-error)
guile>

BTW this is not specific to /debug/ but the same for /list-head/ alone

NB I've got the element "." in the list %load-path to be able to load my own modules.
(set! %load-path (cons "." %load-path)) ; nui0 project addition