opentui: fatal: undefined is not an object (evaluating 'lines().length')

[nigel-dev]

Description

Was working with agent workflows including subagents when it threw this error.

TypeError: undefined is not an object (evaluating 'lines().length')
    at <anonymous> (src/cli/cmd/tui/routes/session/index.tsx:1616:25)
    at runComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:742:22)
    at updateComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:724:3)
    at readSignal (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:660:67)
    at <anonymous> (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:1508:36)
    at <anonymous> (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:1144:20)
    at runComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:742:22)
    at updateComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:724:3)
    at createMemo (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:273:10)
    at untrack (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:475:12)
    at runComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:742:22)
    at updateComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:724:3)
    at devComponent (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:593:3)
    at <anonymous> (src/cli/cmd/tui/routes/session/index.tsx:1638:24)
    at render (src/cli/cmd/tui/routes/session/index.tsx:1670:14)
    at untrack (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:475:12)
    at runComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:742:22)
    at updateComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:724:3)
    at createMemo (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:273:10)
    at untrack (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:475:12)
    at runComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:742:22)
    at updateComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:724:3)
    at devComponent (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:593:3)
    at <anonymous> (src/cli/cmd/tui/routes/session/index.tsx:1388:24)
    at runComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:742:22)
    at updateComputation (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:724:3)
    at runTop (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:833:7)
    at runQueue (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:904:42)
    at completeUpdates (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:860:84)
    at runUpdates (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/dist/dev.js:850:5)
    at setStore (../../node_modules/.bun/solid-js@1.9.9/node_modules/solid-js/store/dist/dev.js:221:5)
    at <anonymous> (src/cli/cmd/tui/context/sync.tsx:124:15)
    at emit (../../node_modules/.bun/@solid-primitives+event-bus@1.1.2+820208fac86deffb/node_modules/@solid-primitives/event-bus/dist/eventBus.js:6:13)
    at emit (../../node_modules/.bun/@solid-primitives+event-bus@1.1.2+820208fac86deffb/node_modules/@solid-primitives/event-bus/dist/emitter.js:92:20)
    at <anonymous> (src/cli/cmd/tui/context/sdk.tsx:20:17)
    at processTicksAndRejections (native:7:39)...

OpenCode version

1.0.65

Steps to reproduce

build a custom agent that then calls subagents. The agent are defined via markdown and are a few hundred lines each. Also have an AGENTS.md thats 2500 lines.

Screenshot and/or share link

Operating System

macOS 26.1

Terminal

Ghostty v1.2.3

[rekram1-node]

does this happen on latest? it may be fixed

[R44VC0RP]

Closing as duplicate of #4254 - same lines().length undefined error.