On 07:54 am, gl...@divmod.com wrote:
2. When filing that ticket, I'd really like a full working example of
inlineCallbacks not showing a traceback to play with
Just to drive that point home, Terry, I found an interesting error in
your initial example. Your example does this:
info = sys.exc_info()
f = failure.Failure(*info)
but sys.exc_info() is a tuple of (type, value, traceback), whereas
Failure takes a tuple of (value, type, traceback). This is why the
default behavior of Failure() with no arguments is to capture the
current exception.
Creating an invalid Failure, as you do here, has some _very_ weird
ramifications for the low-level error-formatting code in the guts of the
logging system; the reason the traceback doesn't get logged is due to an
exception where your ZeroDivisionError instance doesn't have a
__module__ attribute (since it's in the "type" slot).
If I modify your example to pass the arguments in the correct order,
like so:
import sys
from twisted.internet import defer
from twisted.python import failure
d = defer.Deferred()
try:
1 / 0
except Exception:
exc_type, exc_value, exc_tb = sys.exc_info()
f = failure.Failure(exc_value, exc_type, exc_tb)
print "f.tb is %r" % f.tb
d.errback(f)
print "f.tb is %r" % f.tb
then I get a nice traceback, like this:
f.tb is <traceback object at 0xb7c628c4>
f.tb is None
Unhandled error in Deferred:
Traceback (most recent call last):
File "example.py", line 10, in <module>
f = failure.Failure(exc_value, exc_type, exc_tb)
--- <exception caught here> ---
File "example.py", line 7, in <module>
1 / 0
exceptions.ZeroDivisionError: integer division or modulo by zero
which is exactly what Failure is designed to do, i.e. produce useful
tracebacks once the actual "traceback" instance is gone.
So, we still have some diagnosis to do on why you don't seem to be
getting useful tracebacks from inlineCallbacks :). Now, not only can I
not reproduce the bug, your reasoning doesn't make sense any more
either.
_______________________________________________
Twisted-Python mailing list
Twisted-Python@twistedmatrix.com
http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
