[Yum-devel] [PATCH] get retrycode *after* failure_callback has run

[Zdenek Pavlas]

>  This is so the failure handler can change it, right?

Yep

>  And I assume the exceptions aren't in a singleton or something
>  weird, so if the handler calls urlgrabber it won't overwrite previous data?

It's a subclass of IOError so there's some magic in it,
but instances are independent and errno attribute is r/w.
One possible surprise I know of is:

>>> e=URLGrabError(1, "Foo")
>>> e.errno=2
>>> e.errno==2
True
>>> e
URLGrabError(1, 'Foo')

..since str() uses original e.args tuple.

> to know if it can/should change the exception data.

if e.errno==14 and e.code==503: e.errno=-1 # retry

I'd put something like that in the callback,
that's probably specific/safe enough.

> ACK unless you can think of a better way :).

First idea was overriding the errcode with callback's
return value, unless it's None.   Currently it's ignored
and callbacks return None, but we can't be sure.
r/w errno seems much better (atm).