terragrunt-mocked-output-problem
Run this command to reproduce the problem:
AWS_PROFILE=my-profile \
REGION=us-west-1 \
BACKEND_S3_BUCKET=mytfstatebucket \
BACKEND_PREFIX=foo \
BACKEND_DYNAMODB_TABLE=mytfstatetable \
TF_WORKSPACE=whatevs \
TERRAGRUNT_LOG_LEVEL=debug \
terragrunt run-all validate
See what error I got here in /terragrunt-run-all-validate.script.colorless).