fix(tool): flatten resolveChildModel adapter, remove unsafe cast, add compatibility shim and comments

debug-cli-test45.js

@@ -0,0 +1,102 @@
+import { chmod, mkdtemp, readFile, writeFile } from 'node:fs/promises';
+import { spawn } from 'node:child_process';
+import { tmpdir } from 'node:os';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+function waitForExit(child, timeoutMs = 1500) {
+  return new Promise((resolve, reject) => {
+    const timeout = setTimeout(() => {
+      child.kill('SIGKILL');
+      reject(new Error(`wrapper did not exit within ${timeoutMs}ms`));
+    }, timeoutMs);
+
+    child.on('error', (error) => {
+      clearTimeout(timeout);
+      reject(error);
+    });
+
+    child.on('close', (code) => {
+      clearTimeout(timeout);
+      resolve(code ?? 0);
+    });
+  });
+}
+
+async function runWrapperWithFakePi(requestedModel) {
+  const dir = await mkdtemp(join(tmpdir(), 'pi-subagents-wrapper-'));
+  const metaPath = join(dir, 'meta.json');
+  const resultPath = join(dir, 'result.json');
+  const capturePath = join(dir, 'capture.json');
+  const piPath = join(dir, 'pi');
+
+  const resolved = requestedModel;
+  await writeFile(
+    piPath,
+    [
+      `#!${process.execPath}`,
+      "const fs = require('fs');",
+      `const capturePath = ${JSON.stringify(capturePath)};`,
+      "const obj = {",
+      "  PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR: process.env.PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR || '',",
+      "  PI_SUBAGENTS_CHILD: process.env.PI_SUBAGENTS_CHILD || '',",
+      "  argv: process.argv.slice(2)",
+      "};",
+      "fs.writeFileSync(capturePath, JSON.stringify(obj), 'utf8');",
+      "console.log(JSON.stringify({type:'message_end',message:{role:'assistant',content:[{type:'text',text:'done'}],model:'github-copilot/gpt-4o',stopReason:'stop'}}));",
+    ].join('\n'),
+    'utf8',
+  );
+  await chmod(piPath, 0o755);
+
+  await writeFile(
+    metaPath,
+    JSON.stringify(
+      {
+        runId: 'run-1',
+        mode: 'single',
+        task: 'inspect auth',
+        cwd: dir,
+        requestedModel,
+        resolvedModel: resolved,
+        startedAt: '2026-04-09T00:00:00.000Z',
+        sessionPath: join(dir, 'child-session.jsonl'),
+        eventsPath: join(dir, 'events.jsonl'),
+        resultPath,
+        stdoutPath: join(dir, 'stdout.log'),
+        stderrPath: join(dir, 'stderr.log'),
+        transcriptPath: join(dir, 'transcript.log'),
+        tools: ['read', 'grep'],
+        systemPromptPath: join(dir, 'system-prompt.md'),
+      },
+      null,
+      2,
+    ),
+    'utf8',
+  );
+
+  const wrapperPath = join(dirname(fileURLToPath(import.meta.url)), 'src/wrapper/cli.mjs');
+  const child = spawn(process.execPath, [wrapperPath, metaPath], {
+    env: {
+      ...process.env,
+      PATH: dir,
+    },
+    stdio: ['ignore', 'pipe', 'pipe'],
+  });
+
+  const exitCode = await waitForExit(child);
+  console.log('exitCode', exitCode);
+
+  const captureJson = JSON.parse(await readFile(capturePath, 'utf8'));
+  return { flags: captureJson };
+}
+
+(async () => {
+  try {
+    const captured = await runWrapperWithFakePi('github-copilot/gpt-4o');
+    console.log('captured', captured);
+  } catch (err) {
+    console.error('error', err);
+    process.exit(1);
+  }
+})();

debug-run-wrapper.js

@@ -0,0 +1,48 @@
+import { mkdtemp, writeFile, chmod } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { spawn } from 'node:child_process';
+import { dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+async function run() {
+  const dir = await mkdtemp(join(tmpdir(), 'pi-subagents-wrapper-'));
+  const metaPath = join(dir, 'meta.json');
+  const resultPath = join(dir, 'result.json');
+  const capturePath = join(dir, 'capture.json');
+  const piPath = join(dir, 'pi');
+
+  await writeFile(piPath, `#!${process.execPath}\nconst fs = require('fs');\nconst capturePath = ${JSON.stringify(capturePath)};\nconst obj = { PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR: process.env.PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR || '', PI_SUBAGENTS_CHILD: process.env.PI_SUBAGENTS_CHILD || '', argv: process.argv.slice(2) }; fs.writeFileSync(capturePath, JSON.stringify(obj), 'utf8'); console.log(JSON.stringify({type:'message_end',message:{role:'assistant',content:[{type:'text',text:'done'}],model:'github-copilot/gpt-4o',stopReason:'stop'}}));`, 'utf8');
+  await chmod(piPath, 0o755);
+
+  const meta = {
+    runId: 'run-1',
+    mode: 'single',
+    task: 'inspect auth',
+    cwd: dir,
+    requestedModel: 'github-copilot/gpt-4o',
+    resolvedModel: 'github-copilot/gpt-4o',
+    startedAt: '2026-04-09T00:00:00.000Z',
+    sessionPath: join(dir, 'child-session.jsonl'),
+    eventsPath: join(dir, 'events.jsonl'),
+    resultPath,
+    stdoutPath: join(dir, 'stdout.log'),
+    stderrPath: join(dir, 'stderr.log'),
+    transcriptPath: join(dir, 'transcript.log'),
+    tools: ['read', 'grep'],
+    systemPromptPath: join(dir, 'system-prompt.md'),
+  };
+
+  await writeFile(metaPath, JSON.stringify(meta, null, 2), 'utf8');
+
+  const wrapperPath = join(dirname(fileURLToPath(import.meta.url)), 'src/wrapper/cli.mjs');
+  console.log('wrapperPath', wrapperPath, 'metaPath', metaPath);
+  const child = spawn(process.execPath, [wrapperPath, metaPath], { env: { ...process.env, PATH: dir }, stdio: ['ignore','pipe','pipe'] });
+
+  child.stdout.on('data', (c) => console.log('wrapper stdout:', c.toString()));
+  child.stderr.on('data', (c) => console.error('wrapper stderr:', c.toString()));
+
+  child.on('close', (code) => { console.log('wrapper exited', code); process.exit(code ?? 0); });
+}
+
+run().catch(err => { console.error(err); process.exit(1); });

src/presets.ts

@@ -43,6 +43,9 @@ function loadPresetDir(dir: string, source: "global" | "project"): SubagentPrese
     const filePath = join(dir, entry.name);
     let content: string;
     try {
+      // Fail-open: if a preset file is unreadable for any reason, ignore it
+      // rather than failing the entire discovery process. This keeps preset
+      // discovery robust in the presence of partially-broken user files.
       content = readFileSync(filePath, "utf8");
     } catch (_err) {
       continue;
@@ -85,8 +88,11 @@ export function discoverSubagentPresets(cwd: string, options: { homeDir?: string
   }
 
   if (projectPresetsDir) {
+    // Project presets override global presets by name. This is intentional
+    // to let local projects stage or refine presets without modifying the
+    // user's global agent presets. There is no confirmation gate for a
+    // project override; the nearest project takes precedence.
     for (const preset of loadPresetDir(projectPresetsDir, "project")) {
-      // project overrides global by name
       map.set(preset.name, preset);
     }
   }

src/tool.ts

@@ -60,12 +60,15 @@ export function createSubagentTool(deps: {
   listAvailableModelReferences?: typeof listAvailableModelReferences;
   normalizeAvailableModelReference?: typeof normalizeAvailableModelReference;
   parameters?: typeof SubagentParamsSchema;
-  // Compatibility: accept injected resolveChildModel functions with either the
+  // Compatibility: injected resolveChildModel may be the new API
-  // new API ({ callModel?, presetModel? }) or the older test/hooks API
+  // ({ callModel?, presetModel? }) or the older test/hooks API
-  // ({ taskModel?, topLevelModel? }). We adapt at callsite below.
+  // ({ taskModel?, topLevelModel? }). The local adapter below exposes a
+  // flattened, simple boundary that takes only { callModel?, presetModel? }
+  // and adapts to either injected shape internally by providing both key
+  // names when calling the injected resolver.
   resolveChildModel?:
-    | typeof resolveChildModel
+    | ((input: { callModel?: string; presetModel?: string; taskModel?: string; topLevelModel?: string }) => ModelSelection)
-    | ((input: { taskModel?: string; topLevelModel?: string }) => ModelSelection);
+    | typeof resolveChildModel;
   runSingleTask?: (input: {
     cwd: string;
     meta: Record<string, unknown>;
@@ -136,21 +139,22 @@ export function createSubagentTool(deps: {
         step.model = normalizedStepModel;
       }
 
-      const callResolveChildModel = (input: {
+      // Adapter: accept only the flattened shape { callModel?, presetModel? }
-        callModel?: string;
+      // to keep the tool logic simple. If a resolver was injected with the
-        presetModel?: string;
+      // older test/hooks shape, we call it with both key names so it can read
-        taskModel?: string;
+      // the old keys. This is a minimal, internal compatibility shim.
-        topLevelModel?: string;
+      const callResolveChildModel = (input: { callModel?: string; presetModel?: string }) => {
-      }) => {
-        // If an injected resolveChildModel exists, call it with the older-shape
-        // keys (taskModel/topLevelModel) for compatibility. Otherwise, use the
-        // internal resolveChildModel which expects { callModel, presetModel }.
         if (deps.resolveChildModel) {
-          const injected = deps.resolveChildModel as unknown as (arg: { taskModel?: string; topLevelModel?: string }) => unknown;
+          // Provide both naming variants so old and new resolvers both work.
-          return injected({ taskModel: input.callModel ?? input.taskModel, topLevelModel: input.presetModel ?? input.topLevelModel }) as ModelSelection;
+          return deps.resolveChildModel({
+            callModel: input.callModel,
+            presetModel: input.presetModel,
+            taskModel: input.callModel,
+            topLevelModel: input.presetModel,
+          });
         }
 
-        return resolveChildModel({ callModel: input.callModel ?? input.taskModel, presetModel: input.presetModel ?? input.topLevelModel });
+        return resolveChildModel({ callModel: input.callModel, presetModel: input.presetModel });
       };
 
       const runTask = async (input: {
@@ -161,12 +165,7 @@ export function createSubagentTool(deps: {
         step?: number;
         mode: "single" | "parallel" | "chain";
       }) => {
-        const model = callResolveChildModel({
+        const model = callResolveChildModel({ callModel: input.taskModel, presetModel: params.model });
-          callModel: input.taskModel,
-          presetModel: params.model,
-          taskModel: input.taskModel,
-          topLevelModel: params.model,
-        });
 
         const progressFormatter = createProgressFormatter();