worktree setup unconditionally runs pnpm install, breaking zero-dependency repos #430

Activity

1. bradtaylorsf

   added

   readyIssue is ready for automated agent processingIssue is ready for automated agent processing

   in-progressAgent is actively working on this issueAgent is actively working on this issue

   and removed

   readyIssue is ready for automated agent processingIssue is ready for automated agent processing

   on Aug 24, 2026
2. bradtaylorsf

   self-assigned this

   on Aug 24, 2026
3. bradtaylorsf

   added

   in-reviewImplementation complete, PR under reviewImplementation complete, PR under review

   and removed

   in-progressAgent is actively working on this issueAgent is actively working on this issue

   on Aug 24, 2026
4. bradtaylorsf commented on Aug 24, 2026

   

   bradtaylorsf

   on Aug 24, 2026

   OwnerAuthor

   More actions

   Automated implementation complete.

   PR: #435
   Tests: PASSING
   Review: Attached to PR body.

   ---

   Processed by alpha-loop in 575s
5. bradtaylorsf

   added a commit that references this issue on Aug 24, 2026

   feat: worktree setup unconditionally runs pnpm install, breaking zero…

   ...

   This issue will close once commit 847dae3 is merged into the 'master' branch.

   847dae3
6. bradtaylorsf commented on Aug 24, 2026

   

   bradtaylorsf

   on Aug 24, 2026

   OwnerAuthor

   More actions

   AI Implementation Notes

   warning: --full-auto is deprecated; use --sandbox workspace-write instead.
   Reading prompt from stdin...
   2026-08-24T14:45:11.234944Z ERROR codex_core::session::session: failed to load skill /Users/bradtaylor/Documents/GitHub/alpha-loop/.worktrees/session-epic-432-epic-make-an-unattended-run-safe-no-checks-on-issue-prs-install-aborts-dep-free-repos-auth-failure-burns-the-queue/.agents/skills/playwright-testing/SKILL.md: missing YAML frontmatter delimited by ---
   OpenAI Codex v0.144.1

   workdir: /Users/bradtaylor/Documents/GitHub/alpha-loop/.worktrees/session-epic-432-epic-make-an-unattended-run-safe-no-checks-on-issue-prs-install-aborts-dep-free-repos-auth-failure-burns-the-queue
   model: gpt-5.6-sol
   provider: openai
   approval: never
   sandbox: workspace-write [workdir, /tmp, $TMPDIR, /Users/bradtaylor/Documents/GitHub/alpha-loop/.git] (network access enabled)
   reasoning effort: high
   reasoning summaries: none
   session id: 01a0343b-857e-7641-b7cd-98aee488c7fa

   user
   You just implemented GitHub issue #430: worktree setup unconditionally runs pnpm install, breaking zero-dependency repos

   Original Requirements

   worktree.ts:243 runs pnpm install on session-worktree creation regardless of whether the target repo has a package.json. In a deliberately dependency-free repo (plain Node, no package.json), pnpm exits 1 and the whole session aborts at setup.

   Dry-run cannot catch this: install only happens on real worktree creation, so the config validates clean and the failure only appears on the real run.

   Workaround found: SKIP_INSTALL=true alpha-loop run.

   Suggested fix: skip install when no package.json/lockfile exists at repo root (or honor a setup_command: "" / detected-stack "unknown" as no-install), and surface install failures as a named pre-condition error instead of a mid-setup abort.

   Found on alpha-loop 2.4.0, macOS, agent: claude.

   Code Changes (first 5000 chars)

   diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
   index e443cd4..667183a 100644
   --- a/.github/workflows/test.yml
   +++ b/.github/workflows/test.yml
   @@ -4,7 +4,7 @@ on:
   push:
   branches: [master]
   pull_request:

   • branches: [master]

   • branches: [master, 'session/', 'agent/']

   jobs:
   type-check:
   diff --git a/src/lib/worktree.ts b/src/lib/worktree.ts
   index 578edf5..7d41837 100644
   --- a/src/lib/worktree.ts
   +++ b/src/lib/worktree.ts
   @@ -4,7 +4,9 @@
   import { existsSync, mkdirSync, symlinkSync, readlinkSync, unlinkSync, readFileSync, writeFileSync, appendFileSync } from 'node:fs';
   import { join, resolve, basename, relative, isAbsolute } from 'node:path';
   import { exec, shellQuote } from './shell.js';
   +import type { ExecResult } from './shell.js';
   import { log } from './logger.js';
   +import { detectPackageManager } from './init-scan.js';
   import { isWaitingFeedbackStatus } from './session-state.js';
   import type { SessionStatus } from './session.js';

   @@ -51,6 +53,41 @@ export type CleanupWorktreeResult = {
   reason?: string;
   };

   +export type WorktreePreconditionPhase = 'dependency-install';
   +
   +export type WorktreeCommandFailure = ExecResult & {

   • command: string;
     +};

   +/** A setup prerequisite failed before the worktree could enter the build stage. */
   +export class WorktreePreconditionError extends Error {

   • readonly phase: WorktreePreconditionPhase = 'dependency-install';
   • readonly command: string;
   • readonly exitCode: number;
   • readonly stdout: string;
   • readonly stderr: string;
   • readonly attempts: readonly WorktreeCommandFailure[];
   • constructor(attempts: WorktreeCommandFailure[]) {
   • const failure = attempts.at(-1);
   • if (!failure) {

   •  throw new Error('WorktreePreconditionError requires at least one failed command');
     

   • }
   • const detail = failure.stderr || failure.stdout || 'no command output';
   • super(

   •  `Dependency installation pre-condition failed at "${failure.command}" `
     

   •  + `(exit ${failure.exitCode}): ${detail}. `
     

   •  + 'Fix the dependency metadata or install command, or set skip_install: true when installation is intentionally unnecessary.',
     

   • );
   • this.name = 'WorktreePreconditionError';
   • this.command = failure.command;
   • this.exitCode = failure.exitCode;
   • this.stdout = failure.stdout;
   • this.stderr = failure.stderr;
   • this.attempts = attempts;
   • }
     +}

   const ENV_FILES = ['.env', '.env.local', '.env.development', '.env.development.local'];

   function isInsidePath(parent: string, child: string): boolean {
   @@ -237,17 +274,25 @@ export async function setupWorktree(options: SetupWorktreeOptions): Promise<Work
   // Set COMPOSE_PROJECT_NAME so Docker doesn't use "issue-N" as project name
   ensureComposeProjectName(worktreePath, projectDir);

   • // Install dependencies unless skipped
   • if (!skipInstall) {

   • // Install dependencies only for projects with recognized package metadata.
   • const hasPackageMetadata = detectPackageManager(worktreePath) !== 'unknown';
   • if (!skipInstall && hasPackageMetadata) {
     log.info('Installing dependencies in worktree...');

   • const installResult = exec('pnpm install --frozen-lockfile', { cwd: worktreePath });

   • const frozenCommand = 'pnpm install --frozen-lockfile';
   • const installResult = exec(frozenCommand, { cwd: worktreePath });
     if (installResult.exitCode !== 0) {
     // Fall back to regular install

   •  const fallback = exec('pnpm install', { cwd: worktreePath });
     

   •  const fallbackCommand = 'pnpm install';
     

   •  const fallback = exec(fallbackCommand, { cwd: worktreePath });
      if (fallback.exitCode !== 0) {
     

   •    throw new Error(`Dependency installation failed (exit ${fallback.exitCode})`);
     

   •    throw new WorktreePreconditionError([
     

   •      { command: frozenCommand, ...installResult },
     

   •      { command: fallbackCommand, ...fallback },
     

   •    ]);
      }
     

     }
   • } else if (!skipInstall) {
   • log.info('Skipping dependency installation: no package.json or recognized lockfile found at worktree root');
     }

   // Run custom setup command (e.g., Python venv, Ruby bundler, Go modules)
   diff --git a/tests/lib/worktree.test.ts b/tests/lib/worktree.test.ts
   index 9c4b2eb..83e5a00 100644
   --- a/tests/lib/worktree.test.ts
   +++ b/tests/lib/worktree.test.ts
   @@ -1,4 +1,4 @@
   -import { setupWorktree, cleanupWorktree } from '../../src/lib/worktree';
   +import { WorktreePreconditionError, setupWorktree, cleanupWorktree } from '../../src/lib/worktree';

   // Mock dependencies
   jest.mock('../../src/lib/shell', () => ({
   @@ -41,9 +41,13 @@ const mockWriteFile = writeFileSync as jest.MockedFunction

   beforeEach(() => {
   jest.clearAllMocks();

   • // Default: commands succeed, paths don't exist

   • // Default: commands succeed and the synthetic worktree is a Node project.
     mockExec.mockReturnValue({ stdout: '', stderr: '', exitCode: 0 });

   • mockExists.mockReturnValue(false);

   • mockExists.mockImplementat

   Review Summary

   Issue #430 is fully addressed: dependency installation is skipped for repositories without package metadata and install failures are surfaced as typed pre-condition errors.

   Analyze the implementation and list any assumptions or decisions you had to make where the requirements were ambiguous or incomplete. Output ONLY a markdown document with this structure:

   Assumptions

   • (list each assumption made, e.g. "Assumed the date format should be ISO 8601 since it wasn't specified")
   • If no assumptions were needed, write "None — requirements were fully specified"

   Decisions

   • (list each design/implementation decision where multiple valid approaches existed, e.g. "Chose to validate on the server side rather than client side for security")
   • If no notable decisions, write "None — implementation was straightforward"

   Items to Validate

   • (list specific things the user should check, e.g. "Verify the error message wording matches your team's style guide")
   • If nothing needs validation, write "None"

   Keep it concise. Only include genuinely ambiguous items, not obvious implementation choices.
   codex

   Assumptions

   • Assumed detectPackageManager(...) !== 'unknown' accurately represents package metadata at the repository root.
   • Assumed dependency installation should be skipped for all unrecognized or dependency-free repositories, while custom setup commands may still run.
   • Assumed skip_install: true is the preferred user-facing override, despite the reported workaround using SKIP_INSTALL=true.

   Decisions

   • Chose metadata detection instead of adding special handling for setup_command: "" or the detected stack.
   • Preserved the existing pnpm frozen-install-then-fallback behavior rather than selecting the detected package manager.
   • Introduced an exported typed error containing both install attempts and the final failure details.
   • Expanded pull-request CI branch filters to include session/** and agent/**.

   Items to Validate

   • Verify detectPackageManager recognizes every intended root lockfile without classifying unrelated repositories as Node projects.
   • Confirm always invoking pnpm is correct when metadata indicates npm, Yarn, or another package manager.
   • Confirm the skip_install: true guidance and error wording match the supported configuration interface.
   • Confirm the additional CI branch filters are intended scope for issue worktree setup unconditionally runs pnpm install, breaking zero-dependency repos #430.
     tokens used
     12,175

   Assumptions

   • Assumed detectPackageManager(...) !== 'unknown' accurately represents package metadata at the repository root.
   • Assumed dependency installation should be skipped for all unrecognized or dependency-free repositories, while custom setup commands may still run.
   • Assumed skip_install: true is the preferred user-facing override, despite the reported workaround using SKIP_INSTALL=true.

   Decisions

   • Chose metadata detection instead of adding special handling for setup_command: "" or the detected stack.
   • Preserved the existing pnpm frozen-install-then-fallback behavior rather than selecting the detected package manager.
   • Introduced an exported typed error containing both install attempts and the final failure details.
   • Expanded pull-request CI branch filters to include session/** and agent/**.

   Items to Validate

   • Verify detectPackageManager recognizes every intended root lockfile without classifying unrelated repositories as Node projects.
   • Confirm always invoking pnpm is correct when metadata indicates npm, Yarn, or another package manager.
   • Confirm the skip_install: true guidance and error wording match the supported configuration interface.
   • Confirm the additional CI branch filters are intended scope for issue worktree setup unconditionally runs pnpm install, breaking zero-dependency repos #430.

   ---

   Posted by alpha-loop for user validation.