outputs should not be checked during destroy

Module output may need to be evaluated during destroy in order to
possibly be used by providers. The final state however is that all
objects are destroyed, so preconditions should not be evaluated.

internal/terraform/node_output.go

@@ -23,7 +23,8 @@ type nodeExpandOutput struct {
 	Addr         addrs.OutputValue
 	Module       addrs.Module
 	Config       *configs.Output
-	Destroy     bool
+	DestroyPlan  bool
+	DestroyApply bool
 	RefreshOnly  bool
 
 	// Planning is set to true when this node is in a graph that was produced
@@ -52,7 +53,7 @@ func (n *nodeExpandOutput) temporaryValue() bool {
 }
 
 func (n *nodeExpandOutput) DynamicExpand(ctx EvalContext) (*Graph, error) {
-	if n.Destroy {
+	if n.DestroyPlan {
 		// if we're planning a destroy, we only need to handle the root outputs.
 		// The destroy plan doesn't evaluate any other config, so we can skip
 		// the rest of the outputs.
@@ -109,6 +110,7 @@ func (n *nodeExpandOutput) DynamicExpand(ctx EvalContext) (*Graph, error) {
 			Config:       n.Config,
 			Change:       change,
 			RefreshOnly:  n.RefreshOnly,
+			DestroyApply: n.DestroyApply,
 		}
 		log.Printf("[TRACE] Expanding output: adding %s as %T", o.Addr.String(), o)
 		g.Add(o)
@@ -192,8 +194,11 @@ func (n *nodeExpandOutput) ReferenceOutside() (selfPath, referencePath addrs.Mod
 
 // GraphNodeReferencer
 func (n *nodeExpandOutput) References() []*addrs.Reference {
-	// root outputs might be destroyable, and may not reference anything in
-	// that case
+	// DestroyNodes do not reference anything.
+	if n.Module.IsRoot() && n.DestroyApply {
+		return nil
+	}
+
 	return referencesForOutput(n.Config)
 }
 
@@ -208,6 +213,10 @@ type NodeApplyableOutput struct {
 	// Refresh-only mode means that any failing output preconditions are
 	// reported as warnings rather than errors
 	RefreshOnly bool
+
+	// DestroyApply indicates that we are applying a destroy plan, and do not
+	// need to account for conditional blocks.
+	DestroyApply bool
 }
 
 var (
@@ -321,6 +330,9 @@ func (n *NodeApplyableOutput) Execute(ctx EvalContext, op walkOperation) (diags
 		}
 	}
 
+	// Checks are not evaluated during a destroy. The checks may fail, may not
+	// be valid, or may not have been registered at all.
+	if !n.DestroyApply {
 		checkRuleSeverity := tfdiags.Error
 		if n.RefreshOnly {
 			checkRuleSeverity = tfdiags.Warning
@@ -335,6 +347,7 @@ func (n *NodeApplyableOutput) Execute(ctx EvalContext, op walkOperation) (diags
 		if diags.HasErrors() {
 			return diags // failed preconditions prevent further evaluation
 		}
+	}
 
 	// If there was no change recorded, or the recorded change was not wholly
 	// known, then we need to re-evaluate the output

internal/terraform/transform_output.go

@@ -95,7 +95,8 @@ func (t *OutputTransformer) transform(g *Graph, c *configs.Config) error {
 				Addr:         addr,
 				Module:       c.Path,
 				Config:       o,
-				Destroy:     t.removeRootOutputs,
+				DestroyPlan:  t.removeRootOutputs,
+				DestroyApply: t.destroyApply,
 				RefreshOnly:  t.RefreshOnly,
 				Planning:     t.Planning,
 			}