The _hermes-python prologue compared uv.lock / pyproject.toml / pm/lock.json
against facts.json with `-nt`. facts.json is only rewritten on a real sync,
so a checkout that rewrites an input without changing it left the input
newer forever: every run from an activated shell re-sourced activate
(~370ms instead of ~13ms).
pm now records, after every successful full-closure install (no-op syncs
included), a stamp per input under installs/<key>/inputs carrying the exact
mtime the install was verified against, snapshotted before installing so
an input edited mid-install still reads as stale. The prologue re-activates
when any input's mtime differs from its stamp in either direction (branch
switches can move it backwards), when an input is missing, or when there
are no stamps. It globs the stamp dir, so pm owns the only input list.
Also read pyvenv.cfg as utf-8-sig (footgun lane, same file).
hermes_cli.runtime_paths (venv generations, selection, activation) moves to
pm.environments, and gains venv_bin_dir / venv_python / project_python. Every
in-tree caller asks pm for an interpreter now; pm no longer reaches back into
hermes_cli for its own environment layout (pm.packages, pm.extras, pm.ensure,
pm.paths imported hermes_cli.runtime_paths). The three open-coded
"Scripts/python.exe or bin/python" ladders in pm collapse onto venv_python.
hermes_constants.venv_python_path / venv_bin_dir and hermes_cli.runtime_paths
stay as frozen-updater-surface shims only (tests/compat/old_updater_surface.json).
To keep the boot path light, pm/__init__ resolves its facade lazily (PEP 562)
and pm.registry loads the built-in package definitions on first read instead of
at import: `import hermes_bootstrap` now loads pm + pm.environments only (25ms,
was 37ms with the eager facade dragging in the downloader). The stripped-payload
fixtures that ship only pre-import files keep working for the same reason.
Also restores two frozen-surface re-exports the F401 sweep dropped
(banner._github_compare_behind, cua_backend.resolve_cua_driver_cmd).
The demo was scaffolding, not repo content: nothing referenced it but a
docstring.
The tests were 12 against the repo's 1-2 invariant bar. Keep the two that fail
silently when inverted -- the sentinel reaching an exec'd child (the unexported
variable this change fixes) and the prologue's staleness gate, which inverted
either way costs a re-sync per run or a stale environment that looks fine. The
per-OS command pair stays because neither host can observe the other's string.
Dropped the exit-code/message restatement, the no-sentinel cold path, and the
demo-driven harness.
Repo scripts assume the PM-activated environment, so running one without
activation fails much later with a confusing ImportError. Add the two halves
covering both invocation paths:
- scripts/_activation.py: require_activation() exits immediately, naming the
exact command for the caller's shell (source ./activate on POSIX,
. .\activate.ps1 on a native Windows host), before any heavy import.
- scripts/_hermes-python: the POSIX shebang target. `#!/usr/bin/env -S bash -c
'...'` hands itself the target path through bash -c's $0, sources activate,
then execs the interpreter on the same file -- so tracebacks and __file__
still point at the real script and ./scripts/foo.py works from any cwd with
no manual source.
__HERMES_ACTIVATED changes from a bare "1" to the installed-state file the
environment was composed against, so one value carries activation, which
checkout activated it, and a staleness stamp. The prologue compares that file
against uv.lock / pyproject.toml / pm/lock.json with the `-nt` builtin -- no
process spawn -- and re-activates once when the inherited environment predates
its inputs. pm rewrites that file only on a real sync, so the check settles
back to current rather than re-syncing on every run.
A legacy "1" keeps working: require_activation() tests non-emptiness, and the
prologue's [ -e ] fails on it, so it activates once and upgrades.
