A possible (and simple) solution if Pulumi can't find existing AWS resources

This has happened to me a few times, so this is a blog entry mainly intended to help future-me. If Pulumi reports via a pulumi up or pulumi refresh command that some Pulumi-managed AWS resources don’t exist and you know they do via the AWS console or similar, you’ve quite possibly forgotten to set the region. This leads Pulumi to use us-east-1 for S3, SQS, SNS and similarly regional resources instead of the af-south-1 my resources live in. In my case, a simple

export AWS_REGION=af-south-1

sufficed.