Failure diagnosis

Nested lingtai-update reference. Start with read-only identity checks:

bash
lingtai-tui doctor
lingtai-tui version
command -v lingtai-tui lingtai-portal

If /update-tui says unknown, inspect the reported executable and the TUI-owned ~/.lingtai-tui/install.json; do not substitute Homebrew. If a source update fails, confirm its prefix/bin directory still exists and that the requested tag is a strict vX.Y.Z release. If a Homebrew-to-native migration fails, the reported failure line names the exact step (installer command, install.json verification, binary version, or Python runtime) and confirms the original Homebrew install is untouched and still usable; fix the reported native-installer error, then retry with lingtai-tui self-update. Do not substitute brew update or brew upgrade in this migration flow. The migration step itself never uninstalls, unlinks, or deletes the Homebrew formula/keg — do not suggest brew uninstall as part of recovering from a migration failure; a failed migration has nothing to clean up. A successful binary update still requires a fresh process: quit and relaunch the TUI.

If /update-tui or a startup prompt reports the native install as ready but the migration as not complete, this is not a failure to diagnose: install.sh and every artifact check succeeded, but the resolved lingtai-tui on PATH is still the Homebrew one — typically because Homebrew's bin dir (for example /opt/homebrew/bin on Apple Silicon) comes before install.sh's default native bin dir on PATH. This state is expected to repeat on every subsequent interactive launch until the human answers "y" to the concrete "Remove the old Homebrew installation now? y/N]" prompt (default No, so a declined or non-interactive launch leaves it pending), or reorders PATH so the native bin dir resolves first. self-update and doctor only ever report this state and the manual brew uninstall lingtai-ai/lingtai/lingtai-tui command — they never prompt or uninstall. It does not re-run the installer on each detection.

For source-build failures, separate Go module fetches from the portal's npm ci/frontend build. On asset download failure the installer is designed to fall back to a source build; record the release tag, OS/architecture, and the first actionable error rather than retrying blindly. Never paste environment dumps, tokens, or private paths into reports. Python import, venv, or kernel errors are outside this skill; follow the kernel's system-manual runtime/kernel update manual.