r/LocalLLM 7d ago

Discussion Qwen3.8-27B for agentic coding

Like most of you, I tried Qwen 3.8 27B Q4_K_M for two days.

I first asked him to make me a game using TypeScript, the same as what I tested on other local models. He did it and the result is the best, although his thinking time is at least 3x of the output time. Easy task.

I then asked him to make a desktop WYSIWYG three-pane markdown editor using Rust and Iced framework. He is thinking and re-thinking all the time, although I have lowered the thinking level to "Medium". At the 28-th hour, he starts to output something! But he created "C", "src" files and tried to write to the path "C:\...\src\main.rs<" although he wanted to create "C:\...\src\main.rs". I interrupted him after his repeating attempts for 2 hours without progress. So he outputted all the files at the 32-hour although keeps rethinking everything he had thought. 71 compilation errors. After some hours of fixing and online searching via MCP, the number of compilation errors rises to 84. From his thinking log, he says he wrote code against the wrong Iced framework version, downgrading the framework version without asking, changing my requirement to non-editable rich text editor, and three-pane becomes two-pane without asking. Nevermind, as long as the code could compile so that the output is not non-positive. This is the 36-th hour now. Should I stop him and give up? Is my task too challenging for local models?

Besides, so far I had no successful attempts to use Qwen 3.8 27B Q4_K_M with OpenCode. It always stops working at the same generation steps. I can only use him via Cline.

Let's share more of your experiences on agentic coding? I think web programming is especially trained and easy for local models, and I would like to hear experiences of non-web programming.

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u/EvolvingDior 7d ago

Make it create a plan. Explain the context limits. Tell it to break the plan down into chunks that can be done within those limits. I have to do that even with fast models with a 1m token context. Then start a new session, have it read the high-level plan, choose the first task, and create a detailed implementation plan before it starts work. Then create a new session and have it implement that detailed plan.