On 02/27/2016 08:48 AM, Will Angenent wrote:
The code was just to reproduce the exact SQLA error by doing what alembic and
SQLA are doing and additionally determining when the garbage collector runs.
The theory is that garbage gets collected somewhere in between
list(_mapper_registry) in
The code was just to reproduce the exact SQLA error by doing what alembic and
SQLA are doing and additionally determining when the garbage collector runs.
The theory is that garbage gets collected somewhere in between
list(_mapper_registry) in configure_mappers and what happens in
On 02/23/2016 03:38 PM, Will Angenent wrote:
Hi,
I think I’ve finally got to the bottom of it.
This triggers the problem:
- Load a module with some model classes using imp.load_source
- Delete the module from sys.modules
- Add a reference to the model classes using _mapper_registry.keys() so
Hi,
You’re definitely on to something when you say it’s related to garbage
collection and weak references. If I add this:
import gc
gc.disable()
the problem vanishes. I’ve been spending the last couple of hours trying to
reduce the code to the smallest possible case. I’ve reached the point
Well what makes no sense is why these mappers and classes would be
present at all. These classes are strictly defined within an alembic
migration, and make **no** callouts to any other mapped structures in
the application, correct? If so, when the module is garbage
collected, all of the
Hi Mike,
Thanks for your quick response yet again! Here’s the stack trace.
tests/integration/test_database.py:14: in test_database_is_up_to_date
create_test_db(session)
__init__.py:111: in create_test_db
pd_utils.do_import(dtype='locations', ifile=yaml_file)
Hi there -
Can you post a stack trace, and also is your test suite making use of
clear_mappers() ?
The sys.modules activity is not really the primary cause, it's that alembic
makes use of a module object in a temporary way.
> On Feb 21, 2016, at 1:48 PM, Will Angenent
Hi,
We had this interesting issue recently, and I've been trying to figure out
if we deserve this, if this is simply unavoidable, or whether it can be
considered a bug. We're using python 2.7.6, sqlalchemy 1.0.12 and alembic
0.8.4.
Summary:
This statement in
