Summary

In composer shell mode (mod+shift+x), sending any command — including successful ones like gh --help and nonexistent ones like absolutelyfake — triggers a renderer crash:

TypeError: switchFunc(...) is not a function
    at Switch.createMemo.name [as fn]
    at runComputation
    at updateComputation
    ...

Full stack from the session:

TypeError: switchFunc(...) is not a function
    at Switch.createMemo.name [as fn] (http://localhost:5173/@fs/.../node_modules/.vite/deps/chunk-VL2SL2GY.js?v=db12a2de:1549:29)
    at runComputation (.../chunk-VL2SL2GY.js:734:22)
    at updateComputation (.../chunk-VL2SL2GY.js:717:3)
    at runTop (.../chunk-VL2SL2GY.js:827:7)
    at lookUpstream (.../chunk-VL2SL2GY.js:951:87)
    at runTop (.../chunk-VL2SL2GY.js:811:74)
    at runUserEffects (.../chunk-VL2SL2GY.js:924:18)
    at runUpdates (.../chunk-VL2SL2GY.js:844:17)
    at completeUpdates (.../chunk-VL2SL2GY.js:896:17)

Repro

1. bun run dev:desktop on origin/dev (or any branch derived from post-fix: prevent shell failure render crash #174 dev)
2. Open a session (or new session)
3. Press mod+shift+x to enter shell mode
4. Type gh --help (or any command, succeeding or failing)
5. Press Enter / Send
6. Renderer crashes with the Switch error above

Relation to #171 / #174

#174 addressed renderer crashes on failed shell commands by replacing Switch with Show inside packages/ui/src/components/basic-tool.tsx. Manual reverification shows that (a) the crash now also fires on successful commands and (b) it originates from a different <Switch> than the one #174 patched — basic-tool.tsx no longer contains <Switch> in the current tree, so the switchFunc(...) is not a function stack must be from another message-part or tool render path.

Verified

• Reproducible on a clean origin/dev worktree (checked at 4274751ab9, HEAD at issue filing). Not introduced by feat(app): home redesign per #151 #180; #180 does not modify packages/ui or any <Switch> rendering code.

Next steps

1. Identify the specific <Switch> whose <Match when={...}> predicate collapses to undefined when a shell-tool part finishes. Candidate sites: packages/ui/src/components/message-part.tsx (multiple Switch blocks at L647, L861, L1348, L2110, L2185).
2. Decide whether to migrate it to Show/conditional render (same pattern as fix: prevent shell failure render crash #174) or narrow the Match predicate to never return undefined.
3. Add an e2e regression (extending packages/app/e2e/prompt/prompt-shell.spec.ts) covering both success and failure shell output render.

Refs

• [Bug] Shell command failure can crash renderer with Solid Switch TypeError #171 (original shell failure crash issue; closed)
• fix: prevent shell failure render crash #174 (first fix; targeted failure path only)