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2026-06-14 14:30:48 -04:00

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Python

"""
Baked-in build metadata for Hermes Agent.
Source installs report their git revision live via ``git rev-parse`` (see
``hermes_cli/dump.py`` and ``hermes_cli/banner.py``). That doesn't work inside
the published Docker image because ``.dockerignore`` excludes ``.git``, so
those callsites fall back to ``"(unknown)"`` / drop the banner suffix entirely.
To make ``hermes dump`` and the startup banner identify the exact commit the
image was built from, the Docker build writes the build-time ``$HERMES_GIT_SHA``
arg into ``<project_root>/.hermes_build_sha``. This module is the single
read-side helper consumed by both callsites — keeping the lookup in one place
so the file path and missing-file behaviour stay consistent.
Behaviour:
- Returns ``None`` when the file is absent. Source installs and dev images
built without the ``HERMES_GIT_SHA`` build-arg fall through to live-git
resolution in the caller, so non-Docker installs are unaffected.
- Returns ``None`` on any IO / decoding error. The build-sha is a nice-to-have
for support triage; nothing in the CLI is allowed to crash because of it.
- Truncates to ``short`` characters (default 8) to match the format used by
``git rev-parse --short=8`` throughout the codebase.
"""
from __future__ import annotations
from pathlib import Path
from typing import Optional
# Path is resolved relative to this module so it works regardless of cwd —
# matches the pattern used by ``banner._resolve_repo_dir``.
_BUILD_SHA_FILE = Path(__file__).parent.parent / ".hermes_build_sha"
def get_build_sha(short: int = 8) -> Optional[str]:
"""Return the baked-in build SHA, truncated to ``short`` chars, or None.
Reads ``<project_root>/.hermes_build_sha`` if present. The file is
written by the Dockerfile's ``HERMES_GIT_SHA`` build-arg and contains
the full 40-character commit hash on a single line.
"""
try:
if not _BUILD_SHA_FILE.is_file():
return None
sha = _BUILD_SHA_FILE.read_text(encoding="utf-8").strip()
except Exception:
return None
if not sha:
return None
return sha[:short] if short and short > 0 else sha