backport of commit b6a6407783

internal/moduletest/graph/apply.go

@@ -154,8 +154,9 @@ func apply(tfCtx *terraform.Context, run *configs.TestRun, module *configs.Confi
 	}
 
 	applyOpts := &terraform.ApplyOpts{
-		SetVariables:      ephemeralVariables,
-		ExternalProviders: providers,
+		SetVariables:              ephemeralVariables,
+		ExternalProviders:         providers,
+		AllowRootEphemeralOutputs: true,
 	}
 
 	waiter.update(tfCtx, progress, created)

internal/terraform/context_apply.go

@@ -52,7 +52,8 @@ type ApplyOpts struct {
 // as in test cases.
 func (po *PlanOpts) ApplyOpts() *ApplyOpts {
 	return &ApplyOpts{
-		ExternalProviders: po.ExternalProviders,
+		ExternalProviders:         po.ExternalProviders,
+		AllowRootEphemeralOutputs: po.AllowRootEphemeralOutputs,
 	}
 }
 
@@ -292,6 +293,10 @@ func checkApplyTimeVariables(needed collections.Set[string], gotValues InputValu
 func (c *Context) applyGraph(plan *plans.Plan, config *configs.Config, opts *ApplyOpts, validate bool) (*Graph, walkOperation, tfdiags.Diagnostics) {
 	var diags tfdiags.Diagnostics
 
+	if opts == nil {
+		opts = new(ApplyOpts)
+	}
+
 	variables := InputValues{}
 	for name, dyVal := range plan.VariableValues {
 		val, err := dyVal.Decode(cty.DynamicPseudoType)
@@ -316,10 +321,8 @@ func (c *Context) applyGraph(plan *plans.Plan, config *configs.Config, opts *App
 	// FIXME: We should check that all of these match declared variables and
 	// that all of them are declared as ephemeral, because all non-ephemeral
 	// variables are supposed to come exclusively from plan.VariableValues.
-	if opts != nil {
-		for n, vv := range opts.SetVariables {
-			variables[n] = vv
-		}
+	for n, vv := range opts.SetVariables {
+		variables[n] = vv
 	}
 	if diags.HasErrors() {
 		return nil, walkApply, diags
@@ -352,26 +355,22 @@ func (c *Context) applyGraph(plan *plans.Plan, config *configs.Config, opts *App
 		operation = walkDestroy
 	}
 
-	var externalProviderConfigs map[addrs.RootProviderConfig]providers.Interface
-	if opts != nil {
-		externalProviderConfigs = opts.ExternalProviders
-	}
-
 	graph, moreDiags := (&ApplyGraphBuilder{
-		Config:                  config,
-		Changes:                 plan.Changes,
-		DeferredChanges:         plan.DeferredResources,
-		State:                   plan.PriorState,
-		RootVariableValues:      variables,
-		ExternalProviderConfigs: externalProviderConfigs,
-		Plugins:                 c.plugins,
-		Targets:                 plan.TargetAddrs,
-		ActionTargets:           plan.ActionTargetAddrs,
-		ForceReplace:            plan.ForceReplaceAddrs,
-		Operation:               operation,
-		ExternalReferences:      plan.ExternalReferences,
-		Overrides:               plan.Overrides,
-		SkipGraphValidation:     c.graphOpts.SkipGraphValidation,
+		Config:                    config,
+		Changes:                   plan.Changes,
+		DeferredChanges:           plan.DeferredResources,
+		State:                     plan.PriorState,
+		RootVariableValues:        variables,
+		ExternalProviderConfigs:   opts.ExternalProviders,
+		Plugins:                   c.plugins,
+		Targets:                   plan.TargetAddrs,
+		ActionTargets:             plan.ActionTargetAddrs,
+		ForceReplace:              plan.ForceReplaceAddrs,
+		Operation:                 operation,
+		ExternalReferences:        plan.ExternalReferences,
+		Overrides:                 plan.Overrides,
+		SkipGraphValidation:       c.graphOpts.SkipGraphValidation,
+		AllowRootEphemeralOutputs: opts.AllowRootEphemeralOutputs,
 	}).Build(addrs.RootModuleInstance)
 	diags = diags.Append(moreDiags)
 	if moreDiags.HasErrors() {