Two related fixes for Python detection on Windows:
1. py.exe (Python launcher) is missing from per-user installs that
didn't check the launcher option, so 'py -3.X --version' alone
misses real Python installs. User-reported case: clean Win11 +
official Python.org 3.14 install -> 'where py' returned nothing,
our installer offered to install Python again. Both NSIS prereq
page and main.cjs now probe in this order:
1. py.exe launcher (when present)
2. PEP 514 registry: HKLM/HKCU\SOFTWARE\Python\PythonCore\<v>\InstallPath
3. Filesystem: %ProgramFiles%\Python<v>, %LocalAppData%\Programs\Python\Python<v>
Crucially, we never fall back to running 'python.exe' from PATH
on Windows — the WindowsApps stub at %LOCALAPPDATA%\Microsoft\
WindowsApps\python.exe is a redirector that opens the Microsoft
Store window if no Store Python is installed. Triggering that
during boot would be terrible UX. Registry/filesystem probes
never execute the binary.
2. Drop 3.14 from the supported version set. Several Hermes deps
(notably pywinpty, which carries Rust crates like
windows_x86_64_msvc) don't yet publish 3.14 wheels. With wheels
missing, 'pip install -e .' falls back to building from sdist,
which needs a Rust toolchain — users see 'could not compile
windows_x86_64_msvc build script' on first run. install.ps1
sidesteps this by pinning to 3.11 via uv; the desktop installer
doesn't yet have the same uv-managed-Python pathway, so for now
we accept 3.11/3.12/3.13 and tell winget to install 3.11 if
none of those are present. Revisit when the wheel ecosystem
catches up to 3.14 (~early 2026).
Add ripgrep as a third (recommended) prereq alongside Python and Git in
the NSIS prereq detection page, and clean up the page layout based on
on-VM testing.
Why ripgrep
- Hermes' search_files tool calls `rg` directly for content + filename
search (tools/file_operations.py:1382). Falls back to grep/find from
Git Bash when missing — works but slower and noisier (no .gitignore
awareness).
- ~5MB winget install via `BurntSushi.ripgrep.MSVC --scope user` — no
UAC prompt, parallel to how Python installs.
- scripts/install.ps1 already installs ripgrep as part of
Install-SystemPackages; this brings the desktop installer to parity.
Why "recommended" not "required"
- Python and Git are hard requirements: without them the agent runtime
or terminal tool refuses to start. The bootstrapper preflight throws.
- ripgrep is a performance enhancement: missing it just means slower
searches. Page wording reflects this; failure to install is logged
but doesn't show a MessageBox or block.
Layout polish (response to on-VM screenshot review)
- Wizard header now correctly reads "System Requirements" instead of
the leftover "Choose Install Location" from the previous page. Set
via `GetDlgItem $HWNDPARENT 1037/1038` + WM_SETTEXT — the standard
NSIS pattern for overriding the page header on a custom Page.
- Removed redundant in-body title + verbose intro paragraph; the
wizard header IS the title now. Body has one short intro line.
- Group boxes tightened to 26u with content positioned just below the
groupbox title (not top-anchored status + bottom-anchored checkbox
with empty space in the middle). All three panels + footer fit
comfortably in 126u, well under the 140u page limit.
- Checkbox labels simplified: dropped "(per-user, no admin prompt)"
and "(administrator approval required)" suffixes. The footer note
still calls out UAC for Git when relevant.
- Footer text trimmed to fit cleanly without clipping.
Install order (in customInstall macro)
- Python → ripgrep → Git
- Python and ripgrep are silent and run first; Git's UAC prompt comes
last so the user's approval interaction isn't interrupted by silent
activity afterwards.
Skip behavior unchanged
- All three detected → page auto-skips via Abort
- Silent install (/S) → customInstall winget block skips
- User unchecks all → page advances without running winget
Files
- apps/desktop/installer/prereq-check.nsh: ripgrep detection block,
ripgrep page panel + checkbox, ripgrep customInstall block,
GetDlgItem header override, layout reflow
- apps/desktop/README.md: Runtime prerequisites section updated to
list ripgrep as recommended, with manual winget command
The packaged Windows installer now detects Python 3.11+ and Git for Windows
at install time and offers to install missing prereqs via winget. Mirrors
the prereq logic scripts/install.ps1 already runs for CLI installs, so
desktop installer users get the same out-of-the-box experience as
install.ps1 users.
Why
- Hermes' terminal tool calls bash.exe directly (tools/environments/
local.py); on Windows that's Git Bash from Git for Windows. Without it,
the agent fails on the first terminal() call.
- Hermes' Python runtime needs 3.11+. Without it, the desktop bootstrapper
errors out at venv creation.
- Both gaps surfaced on a fresh Windows 11 VM smoke test: VM had Python
pre-installed but no Git, so the agent's first terminal call failed
with "Git Bash isn't installed."
- install.ps1 has had Install-Git + Install-Uv functions for ages. The
desktop installer was the asymmetric outlier.
How — NSIS prereq page
- New file: apps/desktop/installer/prereq-check.nsh (plugged into
electron-builder via build.nsis.include)
- Real Wizard page using nsDialogs, inserted via customPageAfterChangeDir
hook (between the Directory page and InstFiles).
- Group boxes for Python and Git, each showing detection status.
- Pre-checked install checkboxes when winget is available.
- Auto-skips silently if both prereqs are already installed.
- Falls back to manual download URLs when winget itself is missing.
- Detection:
- Python: probes `py -3.11`/`-3.12`/`-3.13`/`-3.14` via the Python
launcher. Microsoft Store "Python stub" (no py.exe) is correctly
classified as not-installed.
- Git: `where git`.
- winget: `where winget` (Win10 1809+ / Win11 with App Installer).
- Install execution (in customInstall macro):
- Python: nsExec::ExecToLog with `--scope user --silent`. Per-user
install, no UAC prompt, output streams to install log.
- Git: ExecShellWait via Windows ShellExecute. Critical because Git
always installs per-machine and triggers UAC; ShellExecute preserves
the foreground focus chain across non-elevated → elevated process
spawns, so UAC actually comes to the foreground. nsExec::ExecToLog
breaks the chain because winget runs hidden.
- Both pass `--disable-interactivity --accept-package-agreements
--accept-source-agreements` to suppress winget's own dialogs.
- Verification: probes Git's standard install locations via FileExists
rather than `where git`. NSIS's process inherits PATH at startup, so
a freshly-installed Git won't be visible to `where` until restart.
- Silent installs (/S) skip the prompts; managed deploys handle prereqs
out-of-band via Group Policy / Intune.
How — Electron-side safety net
- New findGitBash() in main.cjs, parallel to findSystemPython(). Probes
the same locations as tools/environments/local.py:_find_bash() so a
positive result here means the agent's terminal tool will work.
- ensureRuntime now throws a clear, actionable error on Windows when Git
Bash isn't found, matching the existing "Python 3.11+ is required"
error path.
- Catches users the NSIS page doesn't: .msi installer users (NSIS prereq
page doesn't run for MSI), `npm run dev` users, manual installers,
anyone who unchecked the install boxes on the NSIS prereq page.
- All gated on `IS_WINDOWS`; macOS / Linux unaffected.
NSIS build issue (resolved)
- electron-builder defaults to `-WX` (warnings as errors). NSIS optimizer
emits "warning 6010: function not referenced" for our page functions
because Page custom directives don't count as references in its
static-analysis pass. The functions ARE called at runtime when NSIS
invokes the page; the optimizer just can't see it statically.
- Set `build.nsis.warningsAsErrors=false` in package.json so this
spurious warning doesn't fail the build. (Documented option from
electron-builder's nsisOptions.)
Out of scope (filed for future work)
- MSI prereq detection: Windows Installer custom actions are a different
mechanism. Enterprise deploys typically handle prereqs via GP/Intune.
- Bundle PortableGit + python-build-standalone in extraResources for
zero-network installs. ~80MB increase.
- Mac / Linux GUI prereq flows (different installer formats; Xcode CLT
covers most macOS prereqs already; Linux is per-distro hard).
Files
- apps/desktop/installer/prereq-check.nsh (new, ~290 lines NSIS)
- apps/desktop/package.json (build.nsis.include +
warningsAsErrors)
- apps/desktop/electron/main.cjs (findGitBash + preflight)
- apps/desktop/README.md (Runtime prerequisites
section)
Cross-platform impact
- macOS / Linux builds (dist:mac, dist:mac:dmg, dist:mac:zip): nsis
config is ignored entirely; .nsh is dormant.
- npm run dev: .nsh dormant; main.cjs preflight gated on IS_WINDOWS.
- scripts/install.ps1, scripts/install.sh: no reference to any new
files; CLI install paths untouched.
- Hermes CLI / dashboard / gateway: no reference; runtime untouched.
- All checks: node --check on main.cjs and test-desktop.mjs pass;
npm run test:desktop:platforms 4/4 passing; node --test green.
Tested
- npm run dist:win produces signed .exe and .msi without errors.
- Fresh Win11 VM (Python pre-installed, no Git): prereq page renders,
Python check shows detected, Git checkbox pre-checked. Click Next →
Git installs via winget with UAC prompt in foreground.
- After install completes, Hermes launches and the agent's terminal
tool can run bash commands. Verified Git Bash is detected at
`C:\Program Files\Git\bin\bash.exe` by ensureRuntime's preflight.
