Due to the experimental nature of this feature, we do not recommend using it in "production" modules yet and we require an explicit [experimental feature opt-in](https://www.terraform.io/docs/configuration/terraform.html#experimental-language-features) of `variable_validation`. Depending on what feedback we receive, the design of this experimental feature may change significantly in future versions without an automatic upgrade path.
BUG FIXES:
* command/show: Fix an issue with show and aliased providers [GH-23848]
* core: Always clean up empty resources before empty modules [GH-23822]