double free or corruption (out) from psycopg2 connect using python 3.11.6

Question

I have a python application which uses postgres and works fine in a conda envirnment based on python 3.7.3. I am trying to update its conda environment to use a newer python version. I built the new environment ground up by repeatedly running the application to find missing packages and the installing them. Executing this script in the new environment:

import psycopg2 conn = psycopg2.connect("dbname='template1' user='dbuser' host='localhost' password='dbpass'")

Produces: double free or corruption (out) Aborted (core dumped) in the connect.

The postgres version is 10. I see this in /var/log/postgressql/postgresql-10-main.log evey time it's run: 2023-12-07 10:05:52.855 GMT [6618] [unknown]@[unknown] FATAL: no PostgreSQL user name specified in startup packet

psycopg2.version '2.9.9 (dt dec pq3 ext lo64)' python --version Python 3.11.6

Whether or not the username is correct, it shouldn't cause a core dump. Any help appreciated.

Monticule

What version of psycopg2 is that? May it be that it dropped support for postgresql-10? Because postgres is a few major versions behind. – Pyrostat

1) psycopg2 uses libpq which is backwards compatible to Postgres 7.4, so it will handle Postgres 10. 2) How did you install psycopg2? 3) Did you reinstall/rebuild it when you changed the Cond env? – Dreda

That doesn't depend on the username: I'm also getting "FATAL: no PostgreSQL user name specified in startup packet" in my PG logs however using a separate installation of python with the appropriate libraries, out of conda, does not show this issue though the exact same code runs with the same credentials. – Thermogenesis

Hi. I'm still not clear what the issue was that caused my problem, but it has resolved. I did: conda update -n base -c conda-forge conda And the situation improved. Conda then gave me a more useful error message - forget the details sorry - and I was able to resolve problems. Thanks to Adrian, Julaine and Ten for responding to this. Ian. – Monticule

Answer 1

I had the same issue, a workaround for me was downgrading openssl from 3.2.0 to 3.1.4:
conda install openssl=3.1.4
https://github.com/psycopg/psycopg2/issues/1658

Don't know why this is happening, maybe someone has more details.

Another workaround: install psycopg2-binary (or psycopg[binary] if you use psycopg version 3). That version has inbuilt ssl and libpq

Kedgeree

Answer 2

I faced this issue without conda as well, with simply my system openssl library being upgraded to 3.2.0.

An alternative workaround to downgrading openssl is to install psycopg2-binary instead of psycopg2.

Someone came up with a patch in postgresql: https://www.postgresql.org/message-id/[email protected], so you should expect the issue to be resolved fairly soon.

Leningrad