Desktop app: old sessions become unresponsive to new messages; in-app auto-updater downloads but never applies updates

Summary

Two related issues encountered on the macOS desktop app (installed via Homebrew Cask opencode-desktop):

1. Existing chat sessions stop accepting new messages. Old conversations load fine (history renders), but sending a new message appears to send, briefly shows a response starting, then reverts to the pre-send state. The app itself is not frozen — the UI is otherwise responsive, and new sessions could still be used normally.
2. The in-app auto-updater never actually installs updates. On every launch, it checks for updates, finds a newer version, downloads it into ~/Library/Caches/@opencode-aidesktop-updater/pending/, sets its state to ready... and then just stops. The app keeps launching on the old version, re-downloading the same update package every single time instead of applying it.

Environment

• App: OpenCode desktop (Electron, Homebrew Cask opencode-desktop)
• OS: macOS 26.5.1 (Apple Silicon)
• Version at time of issue: running 1.18.2 / Homebrew Caskroom showed 1.17.18 / in-app updater kept finding 1.18.19 but never applied it — three different version numbers reported simultaneously depending on where you looked.

Repro / observed behavior

Issue 1: unresponsive old sessions

• Type a message in an existing (older) chat session → message appears to send → response starts streaming → UI reverts back to the state before the message was sent, as if it never happened.
• Brand-new sessions worked fine throughout.
• ~/.local/share/opencode/log/opencode.log showed no errors — provider requests via github-copilot/claude-sonnet-5 were completing successfully for sessions that did work.
• No crash reports were generated (Crashpad/completed was empty; only an old, unrelated .dmp from several weeks prior was present in Crashpad/pending).
• Renderer log (~/Library/Application Support/ai.opencode.desktop/logs/<timestamp>/renderer.log) showed only benign ResizeObserver loop completed with undelivered notifications noise and one incidental Failed to update terminal Error: PTY session not found: <id> (stale PTY reference from a previous restart, likely unrelated).
• What resolved it: fully quitting the app (osascript -e 'quit app "OpenCode"'), then rm -rf ~/Library/Caches/@opencode-aidesktop-updater, then relaunching. After this, the previously "stuck" session immediately became responsive again and all previously-sent messages/history were visible.
• Root cause is unclear — possibly a stale updater-cache artifact interfering with session state hydration, or some other cached state that gets cleared by a full app data reset. Filing this partly to get help narrowing down the actual cause, since clearing the updater cache is a coincidental-seeming fix.

Issue 2: auto-updater never applies pending update

• main.log on every single launch showed the same sequence:

  app starting { version: '1.18.2', ... }
  auto updater configured { currentVersion: '1.18.2' }
  updater state changed { from: 'idle', to: 'checking' }
  Found version 1.18.19 (url: opencode-desktop-mac-arm64.zip, ...)
  updater state changed { from: 'checking', to: 'downloading' }
  Update has already been downloaded to .../pending/opencode-desktop-mac-arm64.zip
  updater state changed { from: 'downloading', to: 'ready' }
  

  ...and then nothing — the update is never actually applied on subsequent relaunch, across multiple full quit/relaunch cycles over several days.
• Homebrew Cask metadata (brew info --cask opencode-desktop) reported a different installed version (1.17.18 in the Caskroom) than what the running /Applications/OpenCode.app/Contents/Info.plist reported (1.18.2), and the app's own UI reported yet another value (1.17.20) — three different sources of truth disagreeing at the same point in time.
• What resolved it: brew reinstall --cask opencode-desktop (after fully quitting the app) correctly updated the installed app bundle to 1.18.19, confirmed via both brew list --cask --versions opencode-desktop and Info.plist's CFBundleShortVersionString. The in-app Squirrel.Mac-based auto-updater itself never successfully completed an update on its own.

Suggested areas to look at

• Whether the Squirrel.Mac auto-updater integration is correctly triggering quitAndInstall (or equivalent) on relaunch, and why it can sit in ready state indefinitely across many app restarts without applying.
• Whether Homebrew Cask-managed installs and the in-app updater can get into a inconsistent/conflicting state (as observed by the mismatched Caskroom vs. Info.plist vs. in-app-reported versions).
• Whether any cache/session-state file under ~/Library/Application Support/ai.opencode.desktop/ or ~/Library/Caches/@opencode-aidesktop-updater/ can get into a state that blocks existing sessions from accepting new messages, and whether that can be surfaced as a proper error to the user instead of silently reverting the sent message.