Program contains errors.:(NONE).multiplex

Hi,

I'm upgrading from an old MonetDB (11.26.0 source snapshot) to the latest proper release. However, my Python aggregate functions appear to have stopped working (Program contains errors.:(NONE).multiplex):

Running mserver5 with: /usr/local/bin/mserver5 --daemon=yes --set embedded_py=true --dbpath=/data/monetdb-farm/ --set gdk_nr_threads=1 --set max_clients=6

Reproduce with: CREATE FUNCTION test_udf("conum" int) RETURNS STRING LANGUAGE PYTHON3 {{ }};

Create table test("id" uuid, "date" DATE, "number" INT);

select test_udf("number") from test;

Gives: Program contains errors.:(NONE).multiplex

I'm running it via Docker (stock Debian) with only MonetDB installed via apt-get.

Not sure if this is connected: https://www.monetdb.org/bugzilla/show_bug.cgi?id=6378 https://www.monetdb.org/bugzilla/show_bug.cgi?id=6378

Anyone having any similar issues?

Tried compiling from source (April 2019 bransch) as well, no luck

Regards, Niklas