Skip to content

Fix UnicodeDecodeError in Windows wmic process scanning #17049#17074

Closed
oyoyo wants to merge 1 commit into
NousResearch:mainfrom
oyoyo:patch-2
Closed

Fix UnicodeDecodeError in Windows wmic process scanning #17049#17074
oyoyo wants to merge 1 commit into
NousResearch:mainfrom
oyoyo:patch-2

Conversation

@oyoyo

@oyoyo oyoyo commented Apr 28, 2026

Copy link
Copy Markdown

What does this PR do?

Fixes #17049 UnicodeDecodeError and AttributeError in Windows gateway process scanning.

Type of Change

  • Bug fix (non-breaking change which fixes an issue)
  • Critical (blocks hermes setup on Windows)

Related Issue

#17049

Problem

The _scan_gateway_pids() function crashes on Windows systems with non-UTF-8 locales (e.g., Chinese cp936) because:

  1. wmic output uses system code page, not UTF-8: Windows wmic outputs text encoded in the system's locale code page, not UTF-8
  2. UnicodeDecodeError in subprocess reader: When Python tries to decode as UTF-8, it fails with UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0
  3. Cascading failure: The decode error causes result.stdout to become None, then AttributeError when trying to split it

This completely blocks hermes setup on affected Windows systems.

Solution

Added errors='ignore' parameter to the subprocess.run() call. This tells Python to skip undecodable bytes instead of crashing. For process scanning, losing a few non-UTF-8 characters is acceptable and doesn't affect functionality.

Also added a null check for result.stdout as defensive programming.

Changes Made

  • File: hermes_cli/gateway.py
  • Lines: 278-290 (Windows process scanning section)
  • Changes:
    1. Added errors='ignore' to handle non-UTF-8 bytes gracefully
    2. Added null check: or result.stdout is None in the early exit condition

[Bug]: UnicodeDecodeError and AttributeError in Windows gateway process scanning

NousResearch#17049
@alt-glitch alt-glitch added type/bug Something isn't working P2 Medium — degraded but workaround exists comp/cli CLI entry point, hermes_cli/, setup wizard comp/gateway Gateway runner, session dispatch, delivery labels Apr 28, 2026
teknium1 pushed a commit that referenced this pull request Apr 29, 2026
…n Windows non-UTF-8 locales (#17049)

`hermes update` calls `_warn_stale_dashboard_processes()` to warn about
dashboard processes still running the pre-update Python backend. On
Windows, that scan shells out to `wmic process get ProcessId,CommandLine
/FORMAT:LIST` with `text=True` and no explicit encoding.

`wmic` emits text in the system code page (e.g. cp936 on zh-CN locales),
not UTF-8. Without an explicit `encoding=`, Python's default UTF-8
decoder crashes the subprocess reader thread with
`UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 ...`. In
Python 3.11 that crash is silently absorbed: `subprocess.run()` returns
a `CompletedProcess` with `result.stdout = None`, the next line calls
`result.stdout.split("\n")`, and `hermes update` aborts with the
exact `AttributeError: 'NoneType' object has no attribute 'split'`
trace reported in #17049.

Fix: pass `encoding="utf-8", errors="ignore"` so undecodable bytes
cannot take down the reader thread (the parsing only matches the ASCII
prefixes `CommandLine=` and `ProcessId=`, so dropping non-UTF-8 bytes
is safe), and short-circuit when `result.stdout is None` as a defensive
guard for environments where the reader thread still fails for other
reasons.

This is the same root cause as #17074 (which patches
`hermes_cli/gateway._scan_gateway_pids` for the `hermes setup` path).
That PR does not touch `_warn_stale_dashboard_processes`, so
`hermes update` remains broken on the same locales until this lands.

Regression test in `tests/hermes_cli/test_update_stale_dashboard.py`:
- `test_wmic_invoked_with_utf8_ignore_errors` asserts the explicit
  encoding/errors kwargs reach `subprocess.run`.
- `test_wmic_returns_none_stdout_does_not_crash` simulates the
  reader-thread-crashed `result.stdout=None` aftermath and asserts the
  function returns silently instead of raising AttributeError.

Both new tests fail against clean origin/main (7d46484) reproducing
the original AttributeError; both pass with this patch. The remaining
3 failures in `tests/hermes_cli/test_cmd_update.py` and
`test_update_autostash.py` are pre-existing baselines on origin/main —
they reproduce identically without this change and are unrelated to
the wmic scan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
donald131 pushed a commit to donald131/hermes-agent that referenced this pull request May 2, 2026
…n Windows non-UTF-8 locales (NousResearch#17049)

`hermes update` calls `_warn_stale_dashboard_processes()` to warn about
dashboard processes still running the pre-update Python backend. On
Windows, that scan shells out to `wmic process get ProcessId,CommandLine
/FORMAT:LIST` with `text=True` and no explicit encoding.

`wmic` emits text in the system code page (e.g. cp936 on zh-CN locales),
not UTF-8. Without an explicit `encoding=`, Python's default UTF-8
decoder crashes the subprocess reader thread with
`UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 ...`. In
Python 3.11 that crash is silently absorbed: `subprocess.run()` returns
a `CompletedProcess` with `result.stdout = None`, the next line calls
`result.stdout.split("\n")`, and `hermes update` aborts with the
exact `AttributeError: 'NoneType' object has no attribute 'split'`
trace reported in NousResearch#17049.

Fix: pass `encoding="utf-8", errors="ignore"` so undecodable bytes
cannot take down the reader thread (the parsing only matches the ASCII
prefixes `CommandLine=` and `ProcessId=`, so dropping non-UTF-8 bytes
is safe), and short-circuit when `result.stdout is None` as a defensive
guard for environments where the reader thread still fails for other
reasons.

This is the same root cause as NousResearch#17074 (which patches
`hermes_cli/gateway._scan_gateway_pids` for the `hermes setup` path).
That PR does not touch `_warn_stale_dashboard_processes`, so
`hermes update` remains broken on the same locales until this lands.

Regression test in `tests/hermes_cli/test_update_stale_dashboard.py`:
- `test_wmic_invoked_with_utf8_ignore_errors` asserts the explicit
  encoding/errors kwargs reach `subprocess.run`.
- `test_wmic_returns_none_stdout_does_not_crash` simulates the
  reader-thread-crashed `result.stdout=None` aftermath and asserts the
  function returns silently instead of raising AttributeError.

Both new tests fail against clean origin/main (7d46484) reproducing
the original AttributeError; both pass with this patch. The remaining
3 failures in `tests/hermes_cli/test_cmd_update.py` and
`test_update_autostash.py` are pre-existing baselines on origin/main —
they reproduce identically without this change and are unrelated to
the wmic scan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
@teknium1

teknium1 commented May 5, 2026

Copy link
Copy Markdown
Contributor

Closing as redundant — the same wmic encoding fix was independently landed on current main as commit cf83982 ("fix(gateway): handle wmic encoding errors on Windows non-English locales") by @Kailigithub. Thanks for catching the issue on #17049.

@teknium1 teknium1 closed this May 5, 2026
02356abc pushed a commit to 02356abc/hermes-agent that referenced this pull request May 14, 2026
…n Windows non-UTF-8 locales (NousResearch#17049)

`hermes update` calls `_warn_stale_dashboard_processes()` to warn about
dashboard processes still running the pre-update Python backend. On
Windows, that scan shells out to `wmic process get ProcessId,CommandLine
/FORMAT:LIST` with `text=True` and no explicit encoding.

`wmic` emits text in the system code page (e.g. cp936 on zh-CN locales),
not UTF-8. Without an explicit `encoding=`, Python's default UTF-8
decoder crashes the subprocess reader thread with
`UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 ...`. In
Python 3.11 that crash is silently absorbed: `subprocess.run()` returns
a `CompletedProcess` with `result.stdout = None`, the next line calls
`result.stdout.split("\n")`, and `hermes update` aborts with the
exact `AttributeError: 'NoneType' object has no attribute 'split'`
trace reported in NousResearch#17049.

Fix: pass `encoding="utf-8", errors="ignore"` so undecodable bytes
cannot take down the reader thread (the parsing only matches the ASCII
prefixes `CommandLine=` and `ProcessId=`, so dropping non-UTF-8 bytes
is safe), and short-circuit when `result.stdout is None` as a defensive
guard for environments where the reader thread still fails for other
reasons.

This is the same root cause as NousResearch#17074 (which patches
`hermes_cli/gateway._scan_gateway_pids` for the `hermes setup` path).
That PR does not touch `_warn_stale_dashboard_processes`, so
`hermes update` remains broken on the same locales until this lands.

Regression test in `tests/hermes_cli/test_update_stale_dashboard.py`:
- `test_wmic_invoked_with_utf8_ignore_errors` asserts the explicit
  encoding/errors kwargs reach `subprocess.run`.
- `test_wmic_returns_none_stdout_does_not_crash` simulates the
  reader-thread-crashed `result.stdout=None` aftermath and asserts the
  function returns silently instead of raising AttributeError.

Both new tests fail against clean origin/main (7d46484) reproducing
the original AttributeError; both pass with this patch. The remaining
3 failures in `tests/hermes_cli/test_cmd_update.py` and
`test_update_autostash.py` are pre-existing baselines on origin/main —
they reproduce identically without this change and are unrelated to
the wmic scan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
jsboige pushed a commit to jsboige/hermes-agent that referenced this pull request May 14, 2026
…n Windows non-UTF-8 locales (NousResearch#17049)

`hermes update` calls `_warn_stale_dashboard_processes()` to warn about
dashboard processes still running the pre-update Python backend. On
Windows, that scan shells out to `wmic process get ProcessId,CommandLine
/FORMAT:LIST` with `text=True` and no explicit encoding.

`wmic` emits text in the system code page (e.g. cp936 on zh-CN locales),
not UTF-8. Without an explicit `encoding=`, Python's default UTF-8
decoder crashes the subprocess reader thread with
`UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 ...`. In
Python 3.11 that crash is silently absorbed: `subprocess.run()` returns
a `CompletedProcess` with `result.stdout = None`, the next line calls
`result.stdout.split("\n")`, and `hermes update` aborts with the
exact `AttributeError: 'NoneType' object has no attribute 'split'`
trace reported in NousResearch#17049.

Fix: pass `encoding="utf-8", errors="ignore"` so undecodable bytes
cannot take down the reader thread (the parsing only matches the ASCII
prefixes `CommandLine=` and `ProcessId=`, so dropping non-UTF-8 bytes
is safe), and short-circuit when `result.stdout is None` as a defensive
guard for environments where the reader thread still fails for other
reasons.

This is the same root cause as NousResearch#17074 (which patches
`hermes_cli/gateway._scan_gateway_pids` for the `hermes setup` path).
That PR does not touch `_warn_stale_dashboard_processes`, so
`hermes update` remains broken on the same locales until this lands.

Regression test in `tests/hermes_cli/test_update_stale_dashboard.py`:
- `test_wmic_invoked_with_utf8_ignore_errors` asserts the explicit
  encoding/errors kwargs reach `subprocess.run`.
- `test_wmic_returns_none_stdout_does_not_crash` simulates the
  reader-thread-crashed `result.stdout=None` aftermath and asserts the
  function returns silently instead of raising AttributeError.

Both new tests fail against clean origin/main (f5c5125) reproducing
the original AttributeError; both pass with this patch. The remaining
3 failures in `tests/hermes_cli/test_cmd_update.py` and
`test_update_autostash.py` are pre-existing baselines on origin/main —
they reproduce identically without this change and are unrelated to
the wmic scan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
dannyJ848 pushed a commit to dannyJ848/hermes-agent that referenced this pull request May 17, 2026
…n Windows non-UTF-8 locales (NousResearch#17049)

`hermes update` calls `_warn_stale_dashboard_processes()` to warn about
dashboard processes still running the pre-update Python backend. On
Windows, that scan shells out to `wmic process get ProcessId,CommandLine
/FORMAT:LIST` with `text=True` and no explicit encoding.

`wmic` emits text in the system code page (e.g. cp936 on zh-CN locales),
not UTF-8. Without an explicit `encoding=`, Python's default UTF-8
decoder crashes the subprocess reader thread with
`UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 ...`. In
Python 3.11 that crash is silently absorbed: `subprocess.run()` returns
a `CompletedProcess` with `result.stdout = None`, the next line calls
`result.stdout.split("\n")`, and `hermes update` aborts with the
exact `AttributeError: 'NoneType' object has no attribute 'split'`
trace reported in NousResearch#17049.

Fix: pass `encoding="utf-8", errors="ignore"` so undecodable bytes
cannot take down the reader thread (the parsing only matches the ASCII
prefixes `CommandLine=` and `ProcessId=`, so dropping non-UTF-8 bytes
is safe), and short-circuit when `result.stdout is None` as a defensive
guard for environments where the reader thread still fails for other
reasons.

This is the same root cause as NousResearch#17074 (which patches
`hermes_cli/gateway._scan_gateway_pids` for the `hermes setup` path).
That PR does not touch `_warn_stale_dashboard_processes`, so
`hermes update` remains broken on the same locales until this lands.

Regression test in `tests/hermes_cli/test_update_stale_dashboard.py`:
- `test_wmic_invoked_with_utf8_ignore_errors` asserts the explicit
  encoding/errors kwargs reach `subprocess.run`.
- `test_wmic_returns_none_stdout_does_not_crash` simulates the
  reader-thread-crashed `result.stdout=None` aftermath and asserts the
  function returns silently instead of raising AttributeError.

Both new tests fail against clean origin/main (8708ad9) reproducing
the original AttributeError; both pass with this patch. The remaining
3 failures in `tests/hermes_cli/test_cmd_update.py` and
`test_update_autostash.py` are pre-existing baselines on origin/main —
they reproduce identically without this change and are unrelated to
the wmic scan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
gweeteve pushed a commit to gweeteve/hermes-agent that referenced this pull request Jun 2, 2026
…n Windows non-UTF-8 locales (NousResearch#17049)

`hermes update` calls `_warn_stale_dashboard_processes()` to warn about
dashboard processes still running the pre-update Python backend. On
Windows, that scan shells out to `wmic process get ProcessId,CommandLine
/FORMAT:LIST` with `text=True` and no explicit encoding.

`wmic` emits text in the system code page (e.g. cp936 on zh-CN locales),
not UTF-8. Without an explicit `encoding=`, Python's default UTF-8
decoder crashes the subprocess reader thread with
`UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 ...`. In
Python 3.11 that crash is silently absorbed: `subprocess.run()` returns
a `CompletedProcess` with `result.stdout = None`, the next line calls
`result.stdout.split("\n")`, and `hermes update` aborts with the
exact `AttributeError: 'NoneType' object has no attribute 'split'`
trace reported in NousResearch#17049.

Fix: pass `encoding="utf-8", errors="ignore"` so undecodable bytes
cannot take down the reader thread (the parsing only matches the ASCII
prefixes `CommandLine=` and `ProcessId=`, so dropping non-UTF-8 bytes
is safe), and short-circuit when `result.stdout is None` as a defensive
guard for environments where the reader thread still fails for other
reasons.

This is the same root cause as NousResearch#17074 (which patches
`hermes_cli/gateway._scan_gateway_pids` for the `hermes setup` path).
That PR does not touch `_warn_stale_dashboard_processes`, so
`hermes update` remains broken on the same locales until this lands.

Regression test in `tests/hermes_cli/test_update_stale_dashboard.py`:
- `test_wmic_invoked_with_utf8_ignore_errors` asserts the explicit
  encoding/errors kwargs reach `subprocess.run`.
- `test_wmic_returns_none_stdout_does_not_crash` simulates the
  reader-thread-crashed `result.stdout=None` aftermath and asserts the
  function returns silently instead of raising AttributeError.

Both new tests fail against clean origin/main (7d46484) reproducing
the original AttributeError; both pass with this patch. The remaining
3 failures in `tests/hermes_cli/test_cmd_update.py` and
`test_update_autostash.py` are pre-existing baselines on origin/main —
they reproduce identically without this change and are unrelated to
the wmic scan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Egavasyug pushed a commit to Egavasyug/hermes-agent that referenced this pull request Jun 10, 2026
…n Windows non-UTF-8 locales (NousResearch#17049)

`hermes update` calls `_warn_stale_dashboard_processes()` to warn about
dashboard processes still running the pre-update Python backend. On
Windows, that scan shells out to `wmic process get ProcessId,CommandLine
/FORMAT:LIST` with `text=True` and no explicit encoding.

`wmic` emits text in the system code page (e.g. cp936 on zh-CN locales),
not UTF-8. Without an explicit `encoding=`, Python's default UTF-8
decoder crashes the subprocess reader thread with
`UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd0 ...`. In
Python 3.11 that crash is silently absorbed: `subprocess.run()` returns
a `CompletedProcess` with `result.stdout = None`, the next line calls
`result.stdout.split("\n")`, and `hermes update` aborts with the
exact `AttributeError: 'NoneType' object has no attribute 'split'`
trace reported in NousResearch#17049.

Fix: pass `encoding="utf-8", errors="ignore"` so undecodable bytes
cannot take down the reader thread (the parsing only matches the ASCII
prefixes `CommandLine=` and `ProcessId=`, so dropping non-UTF-8 bytes
is safe), and short-circuit when `result.stdout is None` as a defensive
guard for environments where the reader thread still fails for other
reasons.

This is the same root cause as NousResearch#17074 (which patches
`hermes_cli/gateway._scan_gateway_pids` for the `hermes setup` path).
That PR does not touch `_warn_stale_dashboard_processes`, so
`hermes update` remains broken on the same locales until this lands.

Regression test in `tests/hermes_cli/test_update_stale_dashboard.py`:
- `test_wmic_invoked_with_utf8_ignore_errors` asserts the explicit
  encoding/errors kwargs reach `subprocess.run`.
- `test_wmic_returns_none_stdout_does_not_crash` simulates the
  reader-thread-crashed `result.stdout=None` aftermath and asserts the
  function returns silently instead of raising AttributeError.

Both new tests fail against clean origin/main (2e7e9fc) reproducing
the original AttributeError; both pass with this patch. The remaining
3 failures in `tests/hermes_cli/test_cmd_update.py` and
`test_update_autostash.py` are pre-existing baselines on origin/main —
they reproduce identically without this change and are unrelated to
the wmic scan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

comp/cli CLI entry point, hermes_cli/, setup wizard comp/gateway Gateway runner, session dispatch, delivery P2 Medium — degraded but workaround exists type/bug Something isn't working

Projects

None yet

Development

Successfully merging this pull request may close these issues.

[Bug]: UnicodeDecodeError and AttributeError in Windows gateway process scanning

3 participants