error from 'explain what this project does'

[dschneider-wxs]

I followed the quickstart with an existing repo and used the prompt "explain what this project does". I setup and authed Github Copilot. I got this error:

Error: github-copilot request failed with status 400 for model gpt-5.6-terra: Invalid 'input[1].name':
   ▊ empty string. Expected a string with minimum length 1, but got an empty string instead.

I'm not sure where to go from here. tau 0.4.0 from the official installer (used homebrew on macos)

[CasperKristiansson]

This is a Tau 0.4.0 Copilot Responses-API bug, not anything in your repository. The first tool turn has been recorded with an empty function name; on the next loop Tau serializes that as input[1].name: "", which Copilot rejects.

Until that path is fixed, start a clean session on a Copilot model that Tau routes through chat completions:

tau --provider github-copilot --model gpt-4.1 --new-session

Changing model inside the failed session isn't enough, because the empty tool call is already in its history. I reproduced the empty-name serialization on v0.4.0; Tau's bundled catalog routes gpt-4.1 through chat completions rather than the affected Responses path.

[dschneider-wxs]

Thanks, that worked.