Defer import of trytond.backend.
When not using TRYTOND_DATABASE__URI
but the respective entry in trytond.conf
for configuring, nereid tries to open a sqlite database. This is caused by trytond.backend
setting up the database backend as soon as it gets imported. And nereid imports it at the very top of nereid.application
— far before configuring trytond.
This commit solves this issue by deferring the import of trytond.backend
.