Found while root-causing the 33 pre-existing test failures for the rc6 rollup (#406) — 9 of them are this, correctly alarming and misread as host flakiness.
Bug: TmuxSessionRuntime.spawn (container/lib/session_runtime.py) runs tmux new-session -d … without pinning a pane size. Under window-size latest with a stale client reporting 1×1 (a real state on the dev laptop, /dev/ttys000), every newly spawned detached session comes up one column wide. -x/-y alone does NOT fix it — window-size latest overrides it; window-size manual + resize-window does (proven live, four ways).
Why it matters beyond tests: the notify / den-reply path pastes prompts into panes no human has attached to yet. In a 1-column pane the prompt arrives mangled and the agent TUI has no room to render; the session only recovers when someone opens it.
Recommendation: spawn pins a floor at creation — window-size manual on the session it just made plus a resize (e.g. 200×50).
Full account with the experiments: wolts/uxwolt/wolt/drafts/rc6-preexisting-failures.md (uxwolt's tree).
🤖 Generated with Claude Code
Found while root-causing the 33 pre-existing test failures for the rc6 rollup (#406) — 9 of them are this, correctly alarming and misread as host flakiness.
Bug:
TmuxSessionRuntime.spawn(container/lib/session_runtime.py) runstmux new-session -d …without pinning a pane size. Underwindow-size latestwith a stale client reporting 1×1 (a real state on the dev laptop,/dev/ttys000), every newly spawned detached session comes up one column wide.-x/-yalone does NOT fix it —window-size latestoverrides it;window-size manual+resize-windowdoes (proven live, four ways).Why it matters beyond tests: the notify / den-reply path pastes prompts into panes no human has attached to yet. In a 1-column pane the prompt arrives mangled and the agent TUI has no room to render; the session only recovers when someone opens it.
Recommendation:
spawnpins a floor at creation —window-size manualon the session it just made plus a resize (e.g. 200×50).Full account with the experiments:
wolts/uxwolt/wolt/drafts/rc6-preexisting-failures.md(uxwolt's tree).🤖 Generated with Claude Code