[Sqlalchemy-tickets] Issue #3972: SystemError: <built-in function utf_8_decode> returned a result with an error set (zzzeek/sqlalchemy)

[Alan H. <iss...@bi...>]

New issue 3972: SystemError: <built-in function utf_8_decode> returned a result with an error set
https://bitbucket.org/zzzeek/sqlalchemy/issues/3972/systemerror-returned-a-result-with-an

Alan Hamlett:

Getting this error when a `billiard.exceptions.SoftTimeLimitExceeded` exception occurs during a select query:

```
billiard.exceptions.SoftTimeLimitExceeded:
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/app/myapp/amqp.py", line 161, in decorated
    return fn(*args, **kwargs)
  File "/app/myapp/tasks.py", line 1399, in cache_user_summary
    dt=current,
  File "/app/myapp/utils.py", line 983, in get_summary
    use_cache=use_cache)
  File "/app/myapp/utils.py", line 601, in get_combined_durations
    durations = get_durations(user=user, start=start, end=end, use_cache=use_cache)
  File "/app/myapp/utils.py", line 713, in get_durations
    heartbeats.extend(query.all())
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/orm/query.py", line 2703, in all
    return list(self)
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/orm/loading.py", line 90, in instances
    util.raise_from_cause(err)
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/util/compat.py", line 203, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/util/compat.py", line 187, in reraise
    raise value
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/orm/loading.py", line 67, in instances
    fetch = cursor.fetchmany(query._yield_per)
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/engine/result.py", line 1154, in fetchmany
    self.cursor, self.context)
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/engine/base.py", line 1405, in _handle_dbapi_exception
    util.reraise(*exc_info)
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/util/compat.py", line 187, in reraise
    raise value
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/engine/result.py", line 1147, in fetchmany
    l = self.process_rows(self._fetchmany_impl(size))
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/engine/result.py", line 1306, in _fetchmany_impl
    row = self._fetchone_impl()
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/engine/result.py", line 1296, in _fetchone_impl
    self.__buffer_rows()
  File "/app/venv/lib/python3.5/site-packages/sqlalchemy/engine/result.py", line 1283, in __buffer_rows
    self.__rowbuffer = collections.deque(self.cursor.fetchmany(size))
  File "/app/venv/lib/python3.5/encodings/utf_8.py", line 16, in decode
    return codecs.utf_8_decode(input, errors, True)
SystemError: <built-in function utf_8_decode> returned a result with an error set
```

Using Python 3.5.2, SQLAlchemy 1.1.9 and psycopg2 2.7.1.