How long have you run the program? There's a default timeout of 10, 15 minutes (something like that). You can change it if you need to (e.g. if your container takes a super long time to spin up, or you're building a massive DB cluster):
https://www.pulumi.com/docs/intro/concepts/resources/options/customtimeouts/
The expected behavior is that Pulumi should exit gracefully and give as meaningful an error as the upstream API provides. (For AWS Classic, your mileage may vary - Native
should give better error messages because it's a newer backend API.)
Pulumi should never hang forever. If it does, that's a bug. Please submit a GH issue to pulumi/pulumi in GH if this is the case and include a minimal program to reproduce the bug if feasible.
Hope this helps!