gemini-cli - 💡(How to fix) Fix Encoding issue (Mojibake) when reading files containing Chinese characters on Windows

What happened?

In a Windows environment (win32), the agent fails to correctly read and process files containing Chinese characters (UTF-8/Big5). When using tools like read_file or run_shell_command (e.g., type or Get-Content), the output returned to the agent is garbled (Mojibake), making it impossible for the agent to understand the documentation or source code. This severely breaks the "Research" phase of the development lifecycle.

Steps to Reproduce:

1. Create a Markdown or source file with Chinese content.
2. Use the agent to read the file using read_file or run_shell_command.
3. Observe the output in the session history.

Environment:

• OS: Windows (win32)
• Shell: PowerShell / CMD
• Character Set: Potential mismatch between file encoding (UTF-8) and shell output encoding.

Example of Error Output: Output: # MPB.MTNET.MA ??賹??? (Living SPEC) - v6 ?鞈ｆ秘??軋斯踝脤? (Expected readable Chinese characters but got replacement characters and gibberish.)

[ACTION REQUIRED] 📎 PLEASE ATTACH THE EXPORTED CHAT HISTORY JSON FILE TO THIS ISSUE IF YOU FEEL COMFORTABLE SHARING IT.

What did you expect to happen?

1. The output should display readable Chinese characters (e.g., # Project Survival Guide) without any garbled text.
2. The agent should be able to parse the content accurately and base its strategy on the actual text instead of nonsensical characters.
3. The tool should automatically detect and handle file encodings (e.g., UTF-8) correctly within the Windows environment and shell output.

Client information

│ CLI Version 0.42.0 │ │ Git Commit 68e2196d5 │ │ Model gemini-3-flash-preview │ │ Sandbox no sandbox │ │ OS win32 │ │ Auth Method Signed in with Google ([email protected]) │ │ Tier Gemini Code Assist for individuals

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