>>> 1. Start 'emacs -Q'
>>> 2. Record simple macro "C-x ( C-p C-n C-x )"
>>> 3. Bind macro to a key (tested with <f12>, but reproducible with others)
>>>   "C-x C-k b <f12>"
>>> 4. Edit bound macro "C-x C-k e <f12>"
>>> 
>>> Edition fails with following msg:
>>> oclosure--get: Assertion failed: (eq 'closure (car-safe oclosure))
>> Stefan, any ideas?
> 
> Should be fixed now on `master`.

I confirm that with patch problem no longer occurs. Thank you.

Best,
Przemysław Alexander Kamiński