Two fix-ups for #17123:
1. Reword the inline comment in `_warn_stale_dashboard_processes` to
accurately describe the failure mode (locale-dependent decoder, not a
"default UTF-8 decoder") and identify `errors="ignore"` as the
load-bearing protection. Per Copilot's review.
2. Switch `TestWindowsWmicEncoding` from `patch("hermes_cli.main.sys")`
to `monkeypatch.setattr(sys, "platform", "win32")` — the codebase's
canonical pattern (e.g. `tests/hermes_cli/test_auth_ssl_macos.py`).
The MagicMock-replacement approach passed locally on Python 3.12 but
the platform-equality check failed under CI's xdist+Python 3.11,
leaving both new tests red despite the fix being present.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
`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 (7d4648461) 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>
Replace the Linux/macOS pgrep regex ("hermes.*dashboard") with a ps
scan + the same explicit patterns list already used on the Windows
branch and in hermes_cli.gateway._scan_gateway_pids:
hermes dashboard
hermes_cli.main dashboard
hermes_cli/main.py dashboard
The old greedy regex would match any cmdline containing both words —
e.g. a chat session whose argv mentions "dashboard" or an unrelated
grafana/dashboard-server process. Added regression tests for both.
Follow-up tightening on #16881.
The dashboard is a long-lived server process users start and forget.
When hermes update replaces files on disk, the running process holds
the old Python backend in memory while the JS bundle gets updated,
producing a silent frontend/backend mismatch (e.g. v0.11.0 changed
the session token header -- old backends reject every API call).
Scan for running dashboard processes after a successful update (both
git and ZIP paths) and print a warning with their PIDs and restart
instructions. Mirrors the existing pattern for gateway processes.
Fixes#16872
