Files
hermes-agent/hermes_cli/update_cmd_commit.py
Teknium 47dcc975ce fix(update): the tree-move marker records the updater's absolute git for the launch repair
A merge killed while writing hermes_constants.py now reaches the repair (the launcher
imports hermes_bootstrap first), but on a Windows install whose only git is PM's store
copy the repair looked it up through pm, which imports hermes_constants: the lookup
failed, a bare 'git' died with WinError 2 and the tree stayed torn (native mid_git,
run 37198020181). arm_tree_move records the absolute git this run resolved (PATH or
expose_pm_git) and _git_executable prefers it.

(cherry picked from commit 59a744696d3805fdc9fb3f0bf5d5f3b20161cbce)
(cherry picked from commit 8bc8502e336d847a88fc4fd7c408f18d6950377f)
2026-10-06 06:20:31 -07:00

302 lines
13 KiB
Python

"""The single commit point of a source ``hermes update``: everything the tree move needs armed first.
Before git (or the ZIP swap) writes the first file of the new code, three things are durable:
* the interrupted-pull marker (``.git/hermes-update-pull``) naming the commit git moves to, for EVERY
tree move (branch switch, upstream fork pull, the pull itself) so a launch after any exit that left
a torn tree puts the old one back (``_early_recovery.restore_interrupted_pull``);
* the source-completion tail (``venv_sync.arm_completion``) and the host fleet-restart obligation,
so a kill after the move but before the completion child starts still leaves the tail owed to the
next launch (``venv_sync.prepare_launch``) and the restart owed to the next ``hermes update``.
Failures before the move are no-ops: ``disarm_commit_obligations`` puts both obligations back the way
this run found them once the tree is verified at its pre-update commit again.
"""
from __future__ import annotations
import os
import subprocess
import sys
from pathlib import Path
from typing import Optional
from hermes_cli._early_recovery import interrupted_pull_marker, restore_interrupted_pull
from hermes_cli.update_custody import run_git
# What this run found before it armed anything: {path: bytes or None}. None = nothing armed yet.
_armed_snapshot: Optional[dict[Path, Optional[bytes]]] = None
# (git_cmd, (HEAD, branch)) when this run reached its checkout phase, and the checkout it names.
_run_start: Optional[tuple[list, tuple[str, str]]] = None
_obligation_root: Optional[Path] = None
def _owns_live_checkout(root: Path) -> bool:
from hermes_cli.update_cmd import _m
return _m()._pytest_owns_live_checkout(root)
def _obligation_paths(root: Path) -> list[Path]:
from hermes_cli.update_cmd_fleet import _fleet_restart_pending_marker_path
from hermes_cli.update_host_obligation import host_obligation_path
from hermes_cli.venv_sync import completion_pending_path
paths = [completion_pending_path(root), _fleet_restart_pending_marker_path()]
host = host_obligation_path()
if host is not None:
paths.append(host)
return paths
def arm_commit_obligations(root: Path, expected_sha: str) -> None:
"""Owe the completion tail and the fleet restart for ``expected_sha`` BEFORE the tree moves.
Idempotent within a run (the first call snapshots what to restore on a no-op failure). An
unwritable install state raises: nothing has moved yet, and moving without the obligation is
exactly the tail-never-runs state this exists to prevent.
"""
global _armed_snapshot
from hermes_cli.update_cmd_fleet import _write_fleet_restart_pending_marker
from hermes_cli.venv_sync import arm_completion
root = Path(root)
if _owns_live_checkout(root):
return
if _armed_snapshot is None:
snapshot: dict[Path, Optional[bytes]] = {}
for path in _obligation_paths(root):
try:
snapshot[path] = path.read_bytes()
except OSError:
snapshot[path] = None
_armed_snapshot = snapshot
arm_completion(root)
_write_fleet_restart_pending_marker(expected_sha=expected_sha or "")
def disarm_commit_obligations() -> None:
"""Restore both obligations to what this run found: the tree never left its pre-update commit.
Refused (obligations stay armed) unless HEAD is the commit this run STARTED from: a failed later
move (the upstream fork ff after a committed origin pull) is put back to a commit that is
already new code, and that tree still owes its tail.
"""
global _armed_snapshot
if _run_start is not None:
git_cmd, (start_head, _branch) = _run_start
root = Path(_obligation_root) if _obligation_root is not None else None
if root is None or not start_head or head_and_branch(git_cmd, root)[0] != start_head:
return
snapshot, _armed_snapshot = _armed_snapshot, None
for path, data in (snapshot or {}).items():
try:
if data is None:
path.unlink(missing_ok=True)
else:
tmp = path.with_name(path.name + ".restore")
tmp.write_bytes(data)
os.replace(tmp, path)
except OSError:
pass # an owed tail/restart left armed is a retry, never a lost obligation
def commit_obligations_armed() -> bool:
return _armed_snapshot is not None
def arm_tree_move(git_cmd, root: Path, *, pre: str | None, target: str, stash: str | None,
rollback: str | None = None) -> Path:
"""Write the interrupted-pull marker for one git tree move (pre -> target).
``rollback`` (``branch``/``detach``): a syntax rollback that moves HEAD and the index back to
``pre`` before any file; a kill before that step finds HEAD still on ``target`` and the restore
redoes it first.
"""
marker = interrupted_pull_marker(root)
marker.write_text(f"pid={os.getpid()}\npre={pre or ''}\ntarget={target}\nstash={stash or ''}\n"
+ (f"rollback={rollback}\n" if rollback else "")
+ (f"git={git}\n" if (git := _absolute_git(git_cmd)) else ""), encoding="utf-8")
return marker
def _absolute_git(git_cmd) -> str:
"""The git this run moves the tree with, as an absolute path for the next launch's repair.
A Windows install's git is often PM's store copy, on PATH only inside the updater
(``expose_pm_git``); the repair cannot look it up through ``pm`` when the killed move tore a
module ``pm`` imports (``hermes_constants``)."""
import shutil
head = (list(git_cmd) or ["git"])[0] if not isinstance(git_cmd, str) else git_cmd
found = shutil.which(head)
return os.path.abspath(found) if found else ""
def files_added_by(git_cmd, root: Path, pre: str, target: str | None) -> list[str]:
"""Paths ``target`` adds over ``pre``. A rollback's mixed reset un-tracks them and ``reset --hard``
never touches untracked files, so ``drop_added_files`` removes them by name afterwards."""
if not target or target == pre:
return []
cp = run_git(git_cmd, ["diff", "--name-only", "-z", "--no-renames", "--diff-filter=A", pre, target],
cwd=str(root), capture_output=True, text=True, encoding="utf-8", errors="replace",
stdin=subprocess.DEVNULL, timeout=120)
return [p for p in cp.stdout.split("\0") if p] if cp.returncode == 0 else []
def drop_added_files(root: Path, added: list[str]) -> bool:
"""Every one is the move's own file: git refuses to move a checkout over an untracked file.
False when one of them is still there (the caller keeps the marker; the restore retries)."""
root = Path(root)
gone = True
for rel in added:
try:
(root / rel).unlink(missing_ok=True)
except OSError:
gone = False
for parent in sorted({p for rel in added for p in Path(rel).parents if str(p) != "."},
key=lambda p: len(p.parts), reverse=True):
try:
(root / parent).rmdir() # only when empty: anything else inside keeps it
except OSError:
pass
return gone and not any(os.path.lexists(root / rel) for rel in added)
def tree_whole_at(git_cmd, root: Path, sha: str) -> bool:
"""HEAD is ``sha``, no ``index.lock`` is left and no tracked file differs from it."""
def run(*args: str) -> subprocess.CompletedProcess:
return run_git(git_cmd, [*args], cwd=str(root), capture_output=True, text=True, encoding="utf-8",
errors="replace", stdin=subprocess.DEVNULL, timeout=120)
head = run("rev-parse", "-q", "--verify", "HEAD")
if head.returncode != 0 or head.stdout.strip() != sha or (interrupted_pull_marker(Path(root)).parent / "index.lock").exists():
return False
status = run("status", "--porcelain", "-z", "--untracked-files=no")
return status.returncode == 0 and not status.stdout.strip("\0")
def settle_failed_tree_move(root: Path) -> bool:
"""Git exited without finishing a tree move: put back what it wrote, keep the marker if we can't.
True when the tree is verified whole again (at the pre-move commit, or at the target when git got
there anyway); False leaves the marker for the next launch's ``restore_interrupted_pull``.
"""
restore_interrupted_pull(Path(root), after_failure=True)
return not interrupted_pull_marker(Path(root)).is_file()
def requires_other_python(pyproject: bytes | str | None) -> bool:
"""True when a target's ``requires-python`` excludes the running interpreter.
Its startup modules may then use a newer Python's syntax that this interpreter's ``compile()``
cannot judge (PM provisions the required Python with the new code). Unknown -> False: keep
checking, so a real syntax error is never waved through on a guess.
"""
if not pyproject:
return False
import platform
import re
import tomllib
try:
text = pyproject.decode("utf-8") if isinstance(pyproject, bytes) else pyproject
spec = tomllib.loads(text)["project"]["requires-python"]
try:
from packaging.specifiers import SpecifierSet
except ImportError: # the lower bound is the part a Python bump moves
floor = re.search(r">=\s*(\d+)\.(\d+)", spec)
return bool(floor) and sys.version_info[:2] < (int(floor[1]), int(floor[2]))
return not SpecifierSet(spec).contains(platform.python_version(), prereleases=True)
except (KeyError, TypeError, ValueError): # TOMLDecodeError / InvalidSpecifier are ValueErrors
return False
def target_syntax_error(git_cmd, root: Path, target_ref: str, relpaths) -> tuple[str, str] | None:
"""``(path, error)`` for the first startup-critical file that does not compile at ``target_ref``.
Read from the object store, never written to the tree: this runs BEFORE HEAD moves, so a broken
release is refused with the install untouched (the post-pull rollback stays as the backstop).
Skipped for a target that requires a Python this interpreter is not (``requires_other_python``).
"""
pyproject = run_git(git_cmd, ["show", f"{target_ref}:pyproject.toml"], cwd=str(root),
capture_output=True, stdin=subprocess.DEVNULL, timeout=120)
if pyproject.returncode == 0 and requires_other_python(pyproject.stdout):
return None
for rel in relpaths:
shown = run_git(git_cmd, ["show", f"{target_ref}:{rel}"], cwd=str(root), capture_output=True,
stdin=subprocess.DEVNULL, timeout=120)
if shown.returncode != 0:
continue # absent at the target (or unreadable): the post-pull guard has the last word
try:
compile(shown.stdout, rel, "exec", dont_inherit=True)
except (SyntaxError, ValueError) as exc:
return rel, f"{type(exc).__name__}: {exc}"
return None
def head_and_branch(git_cmd, root: Path) -> tuple[str, str]:
def out(*args: str) -> str:
cp = run_git(git_cmd, [*args], cwd=str(root), capture_output=True, text=True, encoding="utf-8", errors="replace",
stdin=subprocess.DEVNULL, timeout=60)
return cp.stdout.strip() if cp.returncode == 0 else ""
return out("rev-parse", "HEAD"), out("rev-parse", "--abbrev-ref", "HEAD")
def checkout_untouched(git_cmd, root: Path, start: tuple[str, str] | None) -> bool:
"""True when the checkout is exactly where this run found it: same HEAD, same branch, no
autostash taken, no tree move armed. Only then may a failed git update fall back to ZIP."""
from hermes_cli.update_cmd_stash import _unrestored_autostash_notice
if start is None or not start[0]:
return False
if _unrestored_autostash_notice() is not None or interrupted_pull_marker(root).is_file():
return False
return head_and_branch(git_cmd, root) == start
def record_run_start(git_cmd, root: Path) -> None:
global _run_start, _obligation_root
_run_start = (list(git_cmd), head_and_branch(git_cmd, root))
_obligation_root = Path(root)
def run_checkout_untouched(root: Path) -> bool:
"""``checkout_untouched`` for this run; True before the checkout phase (nothing can have moved)."""
if _run_start is None:
return True
return checkout_untouched(_run_start[0], Path(root), _run_start[1])
def preflight_refusal(git_cmd, root: Path, target_ref: str, critical_files) -> str | None:
"""Why this update must not start, checked BEFORE the first tree move; ``None`` to proceed.
* a venv owned by another OS user (the completion child used to refuse only after the swap);
* a target whose startup-critical modules do not compile (rollback used to be the only guard).
"""
root = Path(root)
if not _owns_live_checkout(root):
try:
from hermes_cli.venv_sync import refuse_foreign_owned_venv
refuse_foreign_owned_venv(root)
except ImportError:
pass
except Exception as exc: # pm's refusal carries its own remediation text
return f"✗ {exc}"
broken = target_syntax_error(git_cmd, root, target_ref, critical_files)
if broken is not None:
path, error = broken
return (f"✗ The update target has a syntax error in a critical file:\n {path}\n "
+ "\n ".join(error.splitlines()[:6]))
return None
def reset_for_tests() -> None:
global _armed_snapshot, _run_start, _obligation_root
_armed_snapshot = None
_run_start = None
_obligation_root = None