Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

Allow reusing Xcode.app's per-workspace DerivedData (avoid duplicate builds); static XCODEBUILDMCP_DERIVED_DATA_PATH can't map per workspace

Open
#525 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
45/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Active
Tech stack
typescript

Research direction

Start at resolveEffectiveDerivedDataPath and review the per-workspace isolation introduced by #340. Inspect how Xcode.app DerivedData folders expose WorkspacePath in info.plist, then define how matching and fallback paths should work. Done means each workspace can reuse its GUI DerivedData without collisions, while workspaces without an existing folder retain deterministic isolation.

Written by the indexing model from the issue text.

Description

Version: 2.7.0

Problem

For derived data the MCP currently offers two modes, neither of which lets agent builds share Xcode.app's DerivedData per workspace:

  1. Default: per-workspace isolation (#340), but under the MCP's own tree (~/Library/Developer/XcodeBuildMCP/workspaces/<workspace>/DerivedData). This is separate from Xcode.app's ~/Library/Developer/Xcode/DerivedData/<Workspace>-<hash>, so a project built both in the GUI and via the MCP is built and stored twice — double the disk and no incremental reuse across the two.
  2. XCODEBUILDMCP_DERIVED_DATA_PATH: a single static path applied to every call (resolveEffectiveDerivedDataPath returns it verbatim). With multiple workspaces/worktrees, they all collide in one folder → build-product clobbering and full rebuilds.

Request

A mode to resolve derived data to the existing Xcode.app DerivedData folder for each workspace (e.g. matching WorkspacePath in each folder's info.plist), and/or per-workspace configurability instead of a single static override.

This would let a repo built in both Xcode and the MCP share one DerivedData per workspace — no duplication, true incremental reuse between interactive and agent builds.

Workaround

I currently achieve this with a client-side PreToolUse hook that rewrites each build/test call's derivedDataPath to the matching GUI folder (looked up via WorkspacePath in each folder's info.plist), falling back to a deterministic per-workspace path when no GUI folder exists yet. Happy to share it if useful.

Related

  • #340 (per-workspace DerivedData isolation) — implemented isolation, but into the MCP's own tree rather than Xcode.app's.
  • #283 (tilde expansion in config'd derived data path).
Dominant language
TypeScript
Stars
6.4k
Forks
320
PR merge metrics
No merged PRs in 30d

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from getsentry/XcodeBuildMCP

All issues in getsentry/XcodeBuildMCP

Similar issues

More TypeScript issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.