hermes-agent/acp_adapter
Teknium 6098272454 hermes_bootstrap: Windows-only UTF-8 stdio shim for all entry points
Codebase-wide fix for Python-on-Windows UTF-8 footguns, complementing
the earlier execute_code sandbox fixes (which remain load-bearing for
when the sandbox explicitly scrubs child env).

Problem: Python on Windows has two long-standing text-encoding pitfalls:

  1. sys.stdout/stderr are bound to the console code page (cp1252 on
     US-locale installs) — print('café') crashes with UnicodeEncodeError.
  2. Subprocess children don't know to use UTF-8 unless PYTHONUTF8 and/or
     PYTHONIOENCODING are set in their env — so any Python we spawn
     (linters, sandbox children, delegation workers) hits the same bug.

Solution: A tiny bootstrap module (hermes_bootstrap.py) imported as the
first statement of every Hermes entry point:

  - hermes_cli/main.py   (hermes / hermes-agent console_script)
  - run_agent.py         (hermes-agent direct)
  - acp_adapter/entry.py (hermes-acp)
  - gateway/run.py       (messaging gateway)
  - batch_runner.py      (parallel batch mode)
  - cli.py               (legacy direct-launch CLI)

On Windows, the bootstrap:
  - os.environ.setdefault('PYTHONUTF8', '1')       (PEP 540 UTF-8 mode)
  - os.environ.setdefault('PYTHONIOENCODING', 'utf-8')
  - sys.stdout/stderr/stdin.reconfigure(encoding='utf-8', errors='replace')

Children inherit the env vars → they run in UTF-8 mode.
Current process's stdio is reconfigured → print('café') works now.

On POSIX (Linux/macOS), the bootstrap is a complete no-op.  We don't
touch LANG, LC_*, or anything else — users who have intentionally
configured a non-UTF-8 locale aren't affected.  POSIX systems are
already UTF-8 by default in 99% of modern setups, so there's nothing
to fix.

setdefault() (not overwrite) means users who explicitly set PYTHONUTF8=0
or PYTHONIOENCODING=cp1252 in their environment are respected.

What this does NOT fix: bare open(path, 'w') calls in the *parent*
process still default to locale encoding because PYTHONUTF8 is only
read at interpreter init.  A ruff PLW1514 sweep (separate follow-up)
will add explicit encoding='utf-8' at those ~219 call sites for
belt-and-suspenders.

Tests (17): 16 passed, 1 skipped on Windows.
  - Windows: env vars set, stdio reconfigured, child inherits UTF-8 mode
  - POSIX: complete no-op (verified on fake POSIX + skipped on real
    POSIX since we don't have a Linux box in this session)
  - Idempotence: multiple calls safe
  - Graceful degradation: non-reconfigurable streams don't crash
  - User opt-out: explicit PYTHONUTF8=0 is respected
  - Load order: every entry point's FIRST top-level import is
    hermes_bootstrap, enforced by an AST-level parametrized test

pyproject.toml: added hermes_bootstrap to py-modules so it ships with
pip installs.
2026-05-07 19:09:40 -07:00
..
__init__.py feat: restore ACP server implementation from PR #949 (#1254) 2026-03-14 00:09:05 -07:00
__main__.py feat: restore ACP server implementation from PR #949 (#1254) 2026-03-14 00:09:05 -07:00
auth.py feat: restore ACP server implementation from PR #949 (#1254) 2026-03-14 00:09:05 -07:00
entry.py hermes_bootstrap: Windows-only UTF-8 stdio shim for all entry points 2026-05-07 19:09:40 -07:00
events.py fix(acp): improve zed integration 2026-04-17 13:29:26 -07:00
permissions.py fix(permissions): handle None response from ACP request_permission 2026-04-21 05:57:23 -07:00
server.py feat(acp): pass image file attachments through as image_url parts 2026-05-07 09:24:32 -07:00
session.py fix(acp): use SessionDB.replace_messages for atomic history rewrite 2026-05-05 10:05:23 -07:00
tools.py fix(acp): compact Zed tool replay rendering 2026-05-03 01:44:23 -07:00