Compaction Failing to Run on Time

[DamianB-BitFlipper]

Description

I have noticed when using opencode recently with Opus 4.5 (unsure if its the model's fault), compaction fails to run on time and the context balloons too big before compaction can reduce it. See the image

If I try to run /compact after this, the same error repeats. If I write a text prompt, it also fails with the same errors. This forces me to start a new session.

OpenCode version

1.0.203

Steps to reproduce

Just code with Opus long enough until it comes time to compact.

Screenshot and/or share link

Session here: session-ses_49bf.md

Operating System

macOs 15.6.1

Terminal

Ghostty

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• [BUG]: Auto compaction not triggering reliably with Anthropic models #6068: [BUG]: Auto compaction not triggering reliably with Anthropic models - Same issue with Opus 4.5 context balloons and compaction failures
• Session Todo-list is forgotten after compaction #5934: Session Todo-list is forgotten after compaction - Related compaction problem with Opus 4.5 127k context
• prompt is too long when replacing in a file. #5478: prompt is too long when replacing in a file - Similar 'prompt is too long' errors when context approaches limits
• prompt is too long unrecoverable #4845: prompt is too long unrecoverable - Duplicate of same 'prompt too long' error with Opus 4.5

Feel free to ignore if none of these address your specific case.

[DamianB-BitFlipper]

#6068 seems related.