For various reasons a pretty-printer may not work. For example, the underlying data structure may have changed and the pretty-printer is out of date.
The consequences of a broken pretty-printer are severe enough that
gdb provides support for enabling and disabling individual
printers. For example, if print frame-arguments is on,
a backtrace can become highly illegible if any argument is printed
with a broken printer.
Pretty-printers are enabled and disabled by attaching an enabled
attribute to the registered function or callable object. If this attribute
is present and its value is False, the printer is disabled, otherwise
the printer is enabled.