'charmap' codec can't encode character '\U0001f680' in position 4: character maps to <undefined>

文書化されている AgentCore CLI コマンドを使って Windows の失敗を再現し、945 行付近の _sync_stream_with_error_handling にある MyAgent/.venv/Lib/site-packages/bedrock_agentcore/runtime/app.py を調査します。ストリーミングされたレスポンステキストがどのように書き込まれるか、またはエンコードされるかを追跡し、その後、getting-started デモが Windows で Unicode エラーなしに 🚀 文字を処理できることを確認します。

Description

Running the bare AgentCore getting-started demo produces a Unicode error:

'charmap' codec can't encode character '\U0001f680' in position 4: character maps to

Steps to Reproduce

Exactly following Get started with the AgentCore CLI:

1. npm install -g @aws/agentcore
2. agentcore create --name MyAgent --framework Strands --protocol HTTP --model-provider Bedrock --memory none
3. In MyAgent/model/load.py, change the model:

   return BedrockModel(model_id="global.amazon.nova-2-lite-v1:0")

4. cd MyAgent
5. agentcore dev
6. Enter a question; e.g. "What are the highlights of the uv package manager for Python?"

Expected Behavior

The model returns a response with no error.

Actual Behavior

The uv package manager for Python is an extremely fast, all-in-one tool that simplifies Python development by replacing multiple tools with a single, high-performance solution. Here are the key highlights of uv:

🚀 **Error: 'charmap' codec can't encode character '\U0001f680' in position 4: character maps to <undefined>

CLI Version

0.27.0

Operating System

Windows

Additional Context

Initial searches indicated this is related to Python. In any case, in an enterprise framework the first-steps demo should run without issue, across platforms.

From experience, I would guess that one or more layer is making assumptions about the system charset rather than being explicit about which charset is needed.

…

Looking at the console stack trace, the error seems to originate in: MyAgent\\app\\MyAgent\\.venv\\Lib\\site-packages\\bedrock_agentcore\\runtime\\app.py:_sync_stream_with_error_handling:945