Copilot stopped work due to an error Execution failed: Error: Reasoning effort 'medium' is not supported for model 'gemini-3.8-flash'. #68529

Activity

1. github-actions

   locked and limited conversation to collaborators on Oct 13, 2026
2. github-actions

   unlocked this conversation on Oct 13, 2026
3. github-actions

   added

   ai-inspected

   on Oct 13, 2026
4. pelikhan

   assigned

   Copilot

   and

   pelikhan

   on Oct 14, 2026
5. pelikhan

   added

   community

   on Oct 14, 2026
6. Copilot

   linked a pull request that will close this issueOmit unsupported reasoning effort for Gemini Flash Copilot assignments #68726on Oct 14, 2026
7. pelikhan commented on Oct 14, 2026

   

   pelikhan

   on Oct 14, 2026

   Collaborator

   More actions

   @SivaKesava1 could you take a peek at this one?
8. pelikhan

   added

   model-inventory

   model-routing

   bugSomething isn't workingSomething isn't working

   on Oct 14, 2026
9. SivaKesava1 commented on Oct 15, 2026

   

   SivaKesava1

   on Oct 15, 2026

   Collaborator

   More actions

   @pelikhan I looked into this; details are on #68726 (#68726 (comment)). The screenshot is the Copilot cloud agent's own chat, so no gh-aw workflow is involved. I made the same assignment call that gh-aw's assign-to-agent makes, with gemini-3.8-flash at effort medium, and the session ran to completion. Copilot /models lists low, medium and high for Gemini Flash. So this doesn't reproduce today and looks like a Copilot cloud agent problem (or a transient one on 13 Oct), not something gh-aw can fix.

   The Claude-on-Copilot effort 400 we found along the way is a separate gh-aw bug, now #68834.
10. pelikhan

    added

    cluster:model-compatibilityModel selection, alias resolution, provider inventory, and runtime compatibilityModel selection, alias resolution, provider inventory, and runtime compatibility

    on Oct 15, 2026