XCode 26.3 AI assistant's attach file feature doesn't work in a big project

I would like to investigate this issue. File a bug report using Feedback Assistant (https://feedbackassistant.apple.com) and attach a sample project that demonstrates the issue.

Once complete, reply with the FB number below.

Thank you,

 Travis

I can't really share this project :( Maybe there are some other ways I can assist you?

Thanks for asking,

Can you define big project? Is it larger than 100GB? Is it a certain number of files that causes the issue?

What version of macOS are you using and with what hardware?

And what provider are you using? (ChatGPT/Claude/Your own)

Let me know, the more info the better. If I can reproduce this with a sample project, I would like to share this with the relevant engineering team.

 Travis

Project size is around 80 GB. OS: Tahoe 26.2, MacBook: M3 Max. The model provider does not affect the issue.

We use XcodeGen, a multi-project setup, and a Tuist‑based caching solution.

My coworkers on a similar but smaller project don’t have this problem—however, they don’t use a multi‑project setup.

I’ve encountered a similar problem with the “copilotforxcode” extension in its early days. They fixed it somehow.