Automatic retrying on PostgreSQL Serialization Errors (TransactionRollback) seems to be broken for Websauna. This app is a hacky way to verify the issue.

python3 -m venv venv
source venv/bin/activate
pip install -U pip
pip install -r requirements.txt
createdb kaboom_dev
ws-alembic -c my/app/conf/development.ini -x packages=all upgrade head

pserve ws://my/app/conf/development.ini

1. Open http://localhost:6543/kaboom
2. Refresh the page a couple of times
3. If you see an internal server error each time, it is likely that retry support won't work correctly.

pip uninstall websauna
pip install -e "git+https://github.com/koirikivi/websauna.git@fix-view-retrying#egg=websauna"

Then, restart the development server (pserve) and follow the steps in "Verify" again. You should still occassionally see the internal server error view, but most request should now not result in that view.