The extent_info structure is a particularily nasty one to dump portably. Actually, this one is so nasty that I'd rather have none to dump. Interestingly enough, there is only one reachable instance of such a lrecord at dump time : the one in the 'global scope on the default-gutter specifier. It comes from add-tab-to-gutter which creates a zero-length gutter-string with an extend on it, and adds it with a value corresponding to the different image-able console types. So my question is, is it possible to move the add-tab-to-gutter to somewhere after dump time ? Incidentally, how can one get rid of this tab thingy? I already have the toolbar removed, it's not in order to add that :/ OG. PS: Current status : Undumpable types list : - lcrecord-list (15) - opaque_ptr (1) - color-instance (1) - font-instance (1) - range-table (2) - buffer (7) - extent-info (1) - console (5) - stream (1) - device (2) - frame (1) - window (1) Most of these don't have to be dumped anyway.