Two paths let a pre-existing system Node win over the Hermes-managed one.
The desktop backend spawn built its managed-Node PATH entry as
`<home>/node/bin` only. That is the POSIX layout install.sh produces;
install.ps1 unpacks portable Node straight into `%LOCALAPPDATA%\hermes\node`
with node.exe at the root and no `bin\`. On Windows the entry therefore
pointed at a directory that does not exist, and the backend fell through to
whatever Node was already on PATH.
main.ts already had the correct platform-ordered list, behind a "keep this
in sync with iter_hermes_node_dirs()" comment on a second copy of the rule.
The two copies had drifted. Export the ordering from backend-env.ts and have
main.ts consume it so there is one source of truth on the Node side (the
Electron main process cannot import hermes_constants.py, so a mirror is
unavoidable — but one mirror, not two).
install.ps1 appended the node dir to the persisted User PATH instead of
prepending it. The session PATH was already prepended correctly, so this only
bit later processes: any shell opened after install, and a standalone
hermes-setup.exe run that inherits User PATH rather than a curated env, both
resolved a system Node ahead of the bundled one.
Not a bug, for the record: update.rs's prepend list omits the same Windows
root, but it inherits PATH from the desktop, which supplies the correct
entries — so it is redundant rather than broken, and no installer rebuild is
needed for this fix.
Tests: managed dirs lead with the platform-native layout while always
offering both shapes, empty without a home, and every managed dir outranks
the inherited PATH on darwin and win32. The three existing tests that pinned
`entries[1]` by index asserted the old single-dir shape and now assert the
relationship instead.
install.ps1 has no behavioral test here: CI has no PowerShell host, and
AGENTS.md bans source-reading tests (the neighbouring
test_install_ps1_node_path_for_npm.py predates that rule).
Two gaps found auditing the decode-crash cluster:
1. suppress_platform_ver_console() only ran in hermes_cli.main processes;
slash workers, tui_gateway/entry, run_agent, batch_runner, and cli.py
import only hermes_bootstrap and were exposed to both the console
flash and (on Python 3.11.0/3.11.1, which lack CPython's
encoding='locale' fix) a UnicodeDecodeError inside platform.win32_ver()
under PEP 540 — the crash #69413 reported. Move the stub into
hermes_bootstrap so every entry point gets it; the _subprocess_compat
copy stays for non-bootstrap callers.
2. The desktop Electron spawn built the backend env without PYTHONUTF8,
so anything the Python child emitted before hermes_bootstrap ran
(interpreter startup errors, pre-bootstrap tracebacks) decoded with
the locale default. Re-port of PR #56499's env half (echoriver89) to
backend-env.ts (original targeted the deleted backend-env.cjs);
explicit user setting wins.