Terraform

main.tf

# These variables are declared as locals here for brevity but could equally be terraform variables, a terraform http data source, output from another module etc.
locals {
  deployment_targets = {
    # region = aws account id
    "eu-west-1" = "00000000000"
    "eu-west-2" = "11111111111"
  }
  module_version = "1.2.3"
}

provider "aws" {
  for_each = local.deployment_targets # <- not allowed
  alias = "${each.value}${each.value}"
  region = each.key
  assume_role {
    role_arn = "arn:aws:iam::${each.value}:role/Iac"
  }
}

module "cool_module" {
  for_each = local.deployment_targets
  source = "./modules/super_secure_module"

  providers = {
    aws = "aws.${each.value}${each.value}" # <- not allowed
  }
}

module "super_cool_module" {
  source  = "terraform_registry"
  version = local.module_version # <- not allowed
}

module "ultra_cool_module" {
  source  = "github.com/repo/my_module?ref=${local.module_version}" # <- not allowed
}