Merge pull request #23595 from hashicorp/jbardin/deprecate-destroy-references

Update destroy provisioner warnings

command/meta_config.go

@@ -173,10 +173,13 @@ func (m *Meta) dirIsConfigPath(dir string) bool {
 // directory even if loadBackendConfig succeeded.)
 func (m *Meta) loadBackendConfig(rootDir string) (*configs.Backend, tfdiags.Diagnostics) {
 	mod, diags := m.loadSingleModule(rootDir)
+
+	// Only return error diagnostics at this point. Any warnings will be caught
+	// again later and duplicated in the output.
 	if diags.HasErrors() {
 		return nil, diags
 	}
-	return mod.Backend, diags
+	return mod.Backend, nil
 }
 
 // loadValuesFile loads a file that defines a single map of key/value pairs.

configs/provisioner.go

@@ -149,8 +149,11 @@ func onlySelfRefs(body hcl.Body) hcl.Diagnostics {
 				diags = append(diags, &hcl.Diagnostic{
 					Severity: hcl.DiagWarning,
 					Summary:  "External references from destroy provisioners are deprecated",
-					Detail:   "Destroy time provisioners and their connections may only reference values stored in the instance state, which include 'self', 'count.index', or 'each.key'.",
-					Subject:  attr.Expr.Range().Ptr(),
+					Detail: "Destroy-time provisioners and their connection configurations may only " +
+						"reference attributes of the related resource, via 'self', 'count.index', " +
+						"or 'each.key'.\n\nReferences to other resources during the destroy phase " +
+						"can cause dependency cycles and interact poorly with create_before_destroy.",
+					Subject: attr.Expr.Range().Ptr(),
 				})
 			}
 		}