oneiric's Python 2.7 is using an (unreleased) version of unittest which changes the behaviour of TestCase._type_equality_funcs a little. That's fine, in that it's supposed to be a private variable, but bzr is poking at it to try stop used TestCase instances from wasting memory.
bzr needs to become a little more careful in how it pokes at the private variable, and also be adjusted to poke it slightly differently so it will work with Python 2.7.3 (and oneiric's patched 2.7.2).
oneiric's Python 2.7 is using an (unreleased) version of unittest which changes the behaviour of TestCase. _type_equality_ funcs a little. That's fine, in that it's supposed to be a private variable, but bzr is poking at it to try stop used TestCase instances from wasting memory.
bzr needs to become a little more careful in how it pokes at the private variable, and also be adjusted to poke it slightly differently so it will work with Python 2.7.3 (and oneiric's patched 2.7.2).