fix(desktop): update pre-probe source checkouts from main over git

A source checkout without hermes_cli/source_check.py predates release
channels, so the only line it can be on is git. The desktop treated the
missing probe as unsupported and parked the user on a manual
`hermes update --help` card ("This checkout predates desktop
source-channel checks"), so an older non-bundled install could never
update itself from the app.

Report such a checkout as tracking main with an update available and let
apply take the normal git handoff. That update brings in the probe, so
later checks resolve normally. A probe that exists but fails still throws.

apps/desktop/electron/updater/checkout-legacy.test.ts

@@ -7,7 +7,7 @@ import { expect, it, vi } from 'vitest'
 import { type CheckoutStrategyDeps, createCheckoutStrategy } from './checkout'
 import { readSourceUpdate, type SourceUpdate } from './checkout-source'
 
-it('offers manual recovery only for a missing source probe, never for a broken probe', async (): Promise<void> => {
+it('moves a checkout without a source probe to main, but surfaces a broken probe', async (): Promise<void> => {
   const root: string = fs.mkdtempSync(path.join(os.tmpdir(), 'legacy-channel-'))
   const home: string = path.join(root, 'profile')
   const modulePath: string = path.join(root, 'hermes_cli', 'source_check.py')
@@ -31,7 +31,9 @@ it('offers manual recovery only for a missing source probe, never for a broken p
     defaultUpdateBranch: 'main',
     updateHandoffDwellMs: 0,
     resolveUpdateRoot: (): string => root,
-    resolveUpdaterBinary: vi.fn((): string => 'frozen-updater'),
+    // No staged updater and no repo hand-off script: apply ends on the manual
+    // command card, which exposes the target without spawning anything.
+    resolveUpdaterBinary: vi.fn((): null => null),
     remoteGatewayActive: (): boolean => false,
     emitUpdateProgress: vi.fn(),
     rememberLog: vi.fn(),
@@ -54,14 +56,8 @@ it('offers manual recovery only for a missing source probe, never for a broken p
         fs.rmSync(modulePath)
       }
 
-      expect(await strategy.check()).toMatchObject({ supported: false, reason: 'source-probe-unavailable' })
-      const result: Awaited<ReturnType<typeof strategy.apply>> = await strategy.apply()
-      expect(result).toMatchObject({ manual: true, command: 'hermes update --help' })
-      expect(result.message).toContain('branch or channel')
-      expect(result.command).not.toContain('--branch')
-      expect(deps.stopBackendsForUpdate).not.toHaveBeenCalled()
-      expect(deps.resolveUpdaterBinary).not.toHaveBeenCalled()
-      expect(deps.quit).not.toHaveBeenCalled()
+      expect(await strategy.check()).toMatchObject({ supported: true, updateAvailable: true, branch: 'main' })
+      expect(await strategy.apply()).toMatchObject({ ok: true, manual: true, command: 'hermes update' })
     }
 
     fs.writeFileSync(modulePath, 'def main():\n    raise RuntimeError("invalid channel configuration")\n')

apps/desktop/electron/updater/checkout-source.ts

@@ -25,9 +25,6 @@ export interface SourceUpdateProbe {
 
 const execute: typeof execFile.__promisify__ = promisify(execFile)
 
-export const SOURCE_PROBE_RECOVERY: string =
-  'This checkout predates desktop source-channel checks. Run `hermes update --help` in this installation, then choose the intended branch or channel explicitly before updating.'
-
 export function sourceUpdateEnvironment(updateRoot: string, hermesHome: string): NodeJS.ProcessEnv {
   const env: NodeJS.ProcessEnv = {
     ...process.env,

apps/desktop/electron/updater/checkout.ts

@@ -18,7 +18,7 @@ import {
   wrapHandoffForDetachedConsole
 } from '../updater-process'
 
-import { SOURCE_PROBE_RECOVERY, type SourceUpdate, sourceUpdateEnvironment } from './checkout-source'
+import { type SourceUpdate, sourceUpdateEnvironment } from './checkout-source'
 
 import type { UpdaterApplyResultWire, UpdaterMechanism, UpdaterStatusWire, UpdaterStrategy } from './index'
 
@@ -77,10 +77,13 @@ export function createCheckoutStrategy(deps: CheckoutStrategyDeps): UpdaterStrat
   async function check(opts: { force?: boolean } = {}): Promise<UpdaterStatusWire> {
     const root: string = deps.resolveUpdateRoot()
 
+    // A checkout without the source probe predates source channels, so it can
+    // only be on the git line: move it to main. Its update pulls the probe in.
     const status: UpdaterStatusWire = (await deps.readSourceUpdate(root, opts)) ?? {
-      supported: false,
-      reason: 'source-probe-unavailable',
-      message: SOURCE_PROBE_RECOVERY,
+      supported: true,
+      updateAvailable: true,
+      behind: null,
+      branch: deps.defaultUpdateBranch,
       hermesRoot: root
     }
 
@@ -101,16 +104,6 @@ export function createCheckoutStrategy(deps: CheckoutStrategyDeps): UpdaterStrat
   async function applyBody(): Promise<UpdaterApplyResultWire> {
     const status: UpdaterStatusWire = await check({ force: true })
 
-    if (status.reason === 'source-probe-unavailable') {
-      return {
-        ok: true,
-        manual: true,
-        command: 'hermes update --help',
-        message: status.message,
-        hermesRoot: status.hermesRoot
-      }
-    }
-
     if (!status.supported || status.error) {
       return { ok: false, error: status.error ?? status.reason, message: status.message }
     }

website/docs/getting-started/updating.md

@@ -106,9 +106,9 @@ replace a selected release channel with its default branch.
 
 For branch-tracking source installs, the desktop keeps the current named branch
 unless an explicit desktop branch override exists. A detached checkout uses the
-default branch. Older checkouts without source-channel probing show manual
-recovery instructions instead of guessing a target: inspect `hermes update --help`
-in that installation and choose the intended branch or channel before updating.
+default branch. Older checkouts without source-channel probing predate release
+channels, so the desktop updates them from `main` over git; that update brings in
+the probing.
 
 Packaged desktop feed channels derive from their build tag and package owner.
 Changing a source channel is not an MSIX or Store channel switch. Canary builds