In Python 2, to raise a new exception but reuse a traceback requires a
special form of ``raise`` (``raise etype, evalue, tb``).
In Python 3, this is now done via a ``with_traceback`` method on
exception objects.
However this requires a bit of trickery as the former is invalid
syntax in Python 3, hence pycompat bridge created via an exec for
Python 2.
In Python 3:
* various builtins and dict methods were changed to return
view/iterable objects rather than lists
* and the separate Python 2 view/iterable builtins and methods were
removed altogether
This is problematic when using these items as list (which the happens
repeatedly in Odoo), but more viciously when iterating *multiple times*
over them (which also happens, which I've messed up multiple times while
writing this, and which is a pain to debug even when you've just created
the issue).
Convert all code using these to semantics-matching cross-version
helper functions to get the LCD behaviour between P2 and P3, and
forbid the builtins via lint.
issue #8530
Xavier Morel