Bug Description

Summary

Running hermes setup on Windows fails with two related errors:

1. UnicodeDecodeError in the subprocess reader thread due to non-UTF-8 encoded wmic output
2. AttributeError when trying to access result.stdout (which becomes None after the decode error)

Error Messages

Primary Error:

• UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 in position 8177: invalid continuation byte File "C:\Python311\Lib\subprocess.py", line 1597, in _readerthread self._out.write(b''.join(res)) File "", line 322, in decode

Secondary Error (consequence of the first):

• AttributeError: 'NoneType' object has no attribute 'split' File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\gateway.py", line 290, in _scan_gateway_pids for line in result.stdout.split("\n"):

Stack Trace

Exception in thread Thread-1 (_readerthread): Traceback (most recent call last): File "C:\Python311\Lib\threading.py", line 1038, in _bootstrap_inner self.run() File "C:\Python311\Lib\threading.py", line 975, in run self._target(*self._args, **self._kwargs) File "C:\Python311\Lib\subprocess.py", line 1597, in _readerthread self._out.write(b''.join(res)) File "", line 322, in decode UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 in position 8177: invalid continuation byte

Traceback (most recent call last): File "", line 198, in _run_module_as_main File "", line 88, in _run_code File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\main.py", line 10160, in main args.func(args) File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\main.py", line 1522, in cmd_setup run_setup_wizard(args) File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\setup.py", line 3080, in run_setup_wizard _run_first_time_quick_setup(config, hermes_home, is_existing) File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\setup.py", line 3182, in _run_first_time_quick_setup setup_gateway(config) File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\setup.py", line 2405, in setup_gateway service_running = _is_service_running() File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\gateway.py", line 3186, in _is_service_running return len(find_gateway_pids()) > 0 File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\gateway.py", line 370, in find_gateway_pids for pid in _scan_gateway_pids(_exclude, all_profiles=all_profiles): File "C:\Users\feng7\AppData\Local\hermes\hermes-agent\hermes_cli\gateway.py", line 290, in _scan_gateway_pids for line in result.stdout.split("\n"): AttributeError: 'NoneType' object has no attribute 'split'

Steps to Reproduce

1. Run hermes setup on a Windows system (particularly with non-English system locale)
2. During the gateway service detection phase, the error occurs

Expected Behavior

The function should:

• Decode wmic output using the system's code page (or handle encoding errors gracefully)
• Successfully extract process IDs and command lines
• Allow the setup wizard to continue

Actual Behavior

The function crashes with UnicodeDecodeError in the subprocess reader thread, then AttributeError when trying to access result.stdout.

Affected Component

Setup / Installation

Messaging Platform (if gateway-related)

No response

Debug Report

Report       https://paste.rs/3LZ59
agent.log    https://paste.rs/uAhOd
gateway.log  https://paste.rs/RmnLg

Operating System

WIndows 10

Python Version

3.11.5

Hermes Version

0.11.0 (2026.4.23)

Additional Logs / Traceback (optional)

Root Cause Analysis (optional)

Root Cause

The _scan_gateway_pids() function in hermes_cli/gateway.py (lines 278-290) executes the Windows wmic command with text=True and encoding='utf-8' (implicit), but:

1. wmic output is not UTF-8: On Windows systems, especially with non-English locales, wmic outputs text in the system's code page (e.g., cp936 for Chinese, cp1252 for Western European), NOT UTF-8.

2. UnicodeDecodeError in subprocess: When Python tries to decode wmic's output as UTF-8, it fails if the output contains non-UTF-8 bytes (like 0xd0 at position 8177), causing the reader thread to crash.

3. Cascading failure: After the decode error, result.stdout becomes None, leading to the AttributeError.

Current problematic code (lines 278-290):

if is_windows():
    result = subprocess.run(
        ["wmic", "process", "get", "ProcessId,CommandLine", "/FORMAT:LIST"],
        capture_output=True,
        text=True,  # ← Implicitly uses UTF-8 encoding
        timeout=10,
    )
    if result.returncode != 0:
        return []
    current_cmd = ""
    for line in result.stdout.split("\n"):  # ← stdout is None after decode error

Proposed Fix (optional)

Use system encoding

if is_windows():
    result = subprocess.run(
        ["wmic", "process", "get", "ProcessId,CommandLine", "/FORMAT:LIST"],
        capture_output=True,
        text=True,
        encoding='utf-8',  # Explicitly specify
        errors='ignore',   # ← Ignore undecodable bytes instead of crashing
        timeout=10,
    )
    if result.returncode != 0 or result.stdout is None:
        return []
    current_cmd = ""
    for line in result.stdout.split("\n"):

Are you willing to submit a PR for this?

• I'd like to fix this myself and submit a PR