diff --git a/src/main/compiler/CompilerScope.ts b/src/main/compiler/CompilerScope.ts
index 1cc829a..c2ac97e 100644
--- a/src/main/compiler/CompilerScope.ts
+++ b/src/main/compiler/CompilerScope.ts
@@ -58,8 +58,9 @@ export class CompilerScope {
     }
 
     private emitNode(node: NodeView) {
-        this.emitComment(`${node.ref} ${node.nodeUid}`);
-        const sym = this.symbols.getNodeSym(node.nodeUid);
+        const nodeUid = node.nodeUid;
+        this.emitComment(`${node.ref} ${nodeUid}`);
+        const sym = this.symbols.getNodeSym(nodeUid);
         this.code.block(`${this.asyncSym(node)}function ${sym}(params, ctx) {`, `}`, () => {
             if (this.isNodeCached(node)) {
                 this.code.line(`let $c = ctx.cache.get("${node.nodeUid}");`);
@@ -73,17 +74,19 @@ export class CompilerScope {
                 this.emitNodeBodyIntrospect(node);
             }
         });
+        // Emit friendlier function names for stack trace introspection
+        this.code.line(`Object.defineProperty(${sym}, 'name', { value: ${JSON.stringify(nodeUid)} });`);
     }
 
     private emitNodeBodyIntrospect(node: NodeView) {
         const resSym = '$r';
+        const nodeUid = node.nodeUid;
         this.code.line(`let ${resSym};`);
-        this.code.line(`ctx.nodeUid = ${JSON.stringify(node.nodeUid)}`);
         if (this.options.introspect) {
-            const nodeUid = node.nodeUid;
             this.code.block('try {', '}', () => {
                 if (!node.supportsSubgraph()) {
-                    // For subgraphs, pending check is done prior to calling the subgraph the first time.
+                    // For subgraphs, pending check is done prior to calling the subgraph the first time
+                    // (see getSubgraphExpr which calls checkPendingNode instead of doing it here)
                     this.code.line(`ctx.checkPendingNode(${JSON.stringify(nodeUid)});`);
                 }
                 this.code.line(`ctx.nodeEvaluated.emit({` +
diff --git a/src/main/runtime/GraphEvalContext.ts b/src/main/runtime/GraphEvalContext.ts
index 158d714..0d44cff 100644
--- a/src/main/runtime/GraphEvalContext.ts
+++ b/src/main/runtime/GraphEvalContext.ts
@@ -17,17 +17,20 @@ export class GraphEvalContext implements t.GraphEvalContext {
 
     readonly lib = runtimeLib;
 
-    nodeUid = '';
-    pendingNodeUids: Set<string>;
+    // Introspection events delegate to root context.
     nodeEvaluated: Event<t.NodeResult>;
     scopeCaptured: Event<t.ScopeData>;
+    // Pending nodes are stored on root context and inherited by child contexts.
+    pendingNodeUids: Set<string>;
     // Each context maintains its own cache. Subscopes have separate caches
     // and do not delegate to parent contexts.
     cache = new Map<string, any>();
     // Locals are stored per-context. Lookups delegate up the hierarchy.
     locals = new Map<string, any>();
 
-    scopeData: any = undefined;
+    // Scope data is maintained by each context separately.
+    // Compiler populates it via setScopeData when emitting nodes with subgraphs.
+    private scopeData: any = undefined;
 
     constructor(
         readonly parent: GraphEvalContext | null = null,
diff --git a/src/main/types/ctx.ts b/src/main/types/ctx.ts
index f9161ac..741fefe 100644
--- a/src/main/types/ctx.ts
+++ b/src/main/types/ctx.ts
@@ -3,14 +3,9 @@ import { Event } from 'nanoevent';
 import { RuntimeLib } from './runtime-lib.js';
 import { SchemaSpec } from './schema.js';
 
-export interface Deferred {
-    resolve: () => unknown;
-}
-
 export interface GraphEvalContext {
     readonly lib: RuntimeLib;
 
-    nodeUid: string;
     cache: Map<string, any>;
     locals: Map<string, any>;
     nodeEvaluated: Event<NodeResult>;
@@ -40,6 +35,10 @@ export interface GraphEvalContext {
     resolveDeferred(value: unknown): unknown;
 }
 
+export interface Deferred {
+    resolve: () => unknown;
+}
+
 export interface NodeResult {
     nodeUid: string;
     result?: any;