The desktop self-update chain (Desktop -> hermes-setup --update ->
hermes update -> hermes desktop --build-only -> relaunch) rebuilds
Hermes.exe on the user's machine and declared success on bare file
EXISTENCE. A truncated PE (corrupt cached Electron zip / interrupted
extraction or rcedit rewrite / full disk) or a wrong-architecture
unpacked tree therefore shipped as the 'updated' app, which Windows
refuses to load with 'This app can't run on your computer'
(此应用无法在你的电脑上运行) — and the previous working build had
already been wiped by before-pack.mjs, leaving nothing to fall back to.
Fix, in three parts:
- hermes_cli/main.py: post-build integrity gate on Windows
(_ensure_desktop_exe_launchable). Parses the PE header of the freshly
built Hermes.exe — MZ/PE magic, section-table completeness vs file
size (catches truncation), and COFF machine vs the host arch (catches
arm64/x64 mixups). On failure it purges the (likely corrupt) cached
Electron zip, invalidates the content-hash build stamp so the
updater's retry-once genuinely re-downloads and rebuilds, restores
the previous build from the .bak tree when one exists (keeping the
corrupt tree as .corrupt for diagnostics), tells the user the update
was aborted and their old version kept, and exits nonzero.
_desktop_packaged_executable also now prefers a host-loadable PE over
pure newest-mtime when multiple win-*-unpacked trees coexist.
- apps/desktop/scripts/before-pack.mjs: on win32, the previous unpacked
tree is preserved as <appOutDir>.bak (only when it holds the product
exe — partial/corrupt trees still get the plain wipe) instead of
being destroyed, providing the rollback material for the gate above.
Non-Windows behavior is unchanged.
- Behavior-contract tests: tests/hermes_cli/test_desktop_exe_integrity.py
(23 tests — synthetic PE fixtures for truncation/non-PE/arch-mismatch,
rollback semantics, and the build-only exit contract) and 6 new vitest
cases in before-pack.test.mjs for the .bak preservation rules.
Progresses #69179
