hermes - 💡(How to fix) Fix [BUG] PTY write/submit fails on Windows/MSYS (bytes/str conversion) [1 pull requests]

Bug Report: PTY write/submit fails on Windows/MSYS

Summary

When running interactive TUI applications (e.g., freebuff) in PTY mode on Windows/MSYS, the process(action='write') and process(action='submit') tools fail with error:

"argument 'to_write': 'bytes' object cannot be converted to 'PyString'"

Environment

• OS: Windows 11 Pro (Build 26200.8457)
• Shell: MSYS2 bash (Git Bash / MINGW64)
• Hermes Version: Latest (as of 2026-05-24)
• Python: 3.11

Steps to Reproduce

1. Launch interactive TUI: terminal(command="freebuff", pty=True, background=True)
2. Send input: process(action='write', data=' ')
3. Error: "argument 'to_write': 'bytes' object cannot be converted to 'PyString'"

Expected Behavior

• process(write) sends text to PTY session
• process(submit) sends text + Enter
• TUI application receives input and responds

Actual Behavior

• Encoding error prevents input from being sent
• TUI hangs waiting for input
• Only process(action='poll') works (reading output)

Affected Use Cases

1. Freebuff - AI coding assistant with interactive TUI
2. vim, htop, ncdu and other interactive CLI tools
3. Package managers with interactive prompts
4. SSH sessions requiring password input
5. Python REPL and other interactive interpreters

Root Cause

Type mismatch in PTY write function: receives str, tries to write as bytes, conversion fails.

Files Likely Affected

• hermes_cli/commands.py
• tools/process.py
• _pty_backend.py or similar

Proposed Fix

def write_to_pty(session_id, data):
    if isinstance(data, str):
        data = data.encode('utf-8')
    # ... rest of write logic

Priority

High - Blocks all interactive CLI tool usage on Windows.

Additional Context

• Works correctly on Linux (tested on WSL Ubuntu)
• Only affects Windows/MSYS environment
• Terminal launch works; only interactive I/O is broken

Reported by: Ilya (via Hermes Agent) Date: 2026-05-24 Contact: [email protected]