rust-synapse-compress-state: synapse_auto_compressor panics on start after using the history delete api to remove remote events

I’m always calling the following script in preparation of a compressor run:

#!/bin/bash

# Clean up synapse_auto_compressor state tables.
#
# The compressor doesn't take into account
# - deleted rooms
# - state groups which got deleted either as unreferenced 
#   or due to retention time
#
# Procedure:
# 1. Delete progress related to deleted rooms
# 2. Delete progress for rooms where one of the referenced state groups
#    no longer exist
# 3. Replicate changes from state_compressor_state to state_compressor_progress

set -e -u -o pipefail

export PGHOST=$1
export PGDATABASE=$2
export PGUSER=$3
export PGPASSWORD=$4

SCRIPT=$(basename $0)

echo "[$(date -u '+%Y-%m-%dT%H:%M:%SZ') INFO ${SCRIPT}]" Starting

psql <<_EOF
BEGIN;

DELETE
FROM state_compressor_state AS scs
WHERE NOT EXISTS
    (SELECT *
     FROM rooms AS r
     WHERE r.room_id = scs.room_id);

DELETE
FROM state_compressor_state AS scs
WHERE scs.room_id in
    (SELECT DISTINCT room_id
     FROM state_compressor_state AS scs2
     WHERE scs2.current_head IS NOT NULL
       AND NOT EXISTS
         (SELECT *
          FROM state_groups AS sg
          WHERE sg.id = scs2.current_head));

DELETE
FROM state_compressor_progress AS scp
WHERE NOT EXISTS
    (SELECT *
     FROM state_compressor_state AS scs
     WHERE scs.room_id = scp.room_id);

COMMIT;
_EOF

echo "[$(date -u '+%Y-%m-%dT%H:%M:%SZ') INFO ${SCRIPT}]" Finished

I’m not sure if this is helpful, but deleting the relevant room entries into state_compressor_state and state_compressor_progress. At least made the auto compressor resume working for me.

Thanks for trying that—I wonder what’s happened there?