Comment 0 for bug 1800508

Description
==============
If an error occurs during instance creation, the user won't be able to know what exactly happened with the VM that remains always building. As usual, the workflow of creating a VM was interrupted by an exception in the method schedule_and_build_instances, so the result would be the VM is in 'error' state.

Steps to reproduce
=====================
1) Create a VM;
2) Inject an out-of-range value in 'schedule_and_build_instances/args/build_requests>nova_object.data/instance/nova_object.data/instance_type_id', this will be enough to cause a DBError. For instance, it can be used the 1E+22 value.
3) An exception will be thrown, but seems there no exist an appropriate action when this DBError happens.

Expected result
==================
The VM is put in 'error' state

Actual result
================
The VM is in 'build' state indeterminately, and the user never will know (without searching in the logs) what happened with the VM.

Environment
==============
Devstack/Stable/Queens.

Logs & Configs
=================
Logs attached.