Bug Description

Claude Code's statusLine feature (configured in settings.json as a command whose stdout is rendered at the bottom of the TUI) does not render reliably when Claude Code runs inside emdash. Symptoms observed with the claude-hud plugin:

• The statusLine additions are missing entirely, or
• They flicker briefly while typing, then disappear again, or
• They only appear after moving focus away from the Claude Code terminal pane

Steps to Reproduce

1. Install claude-hud: run claude-hud:setup from within a Claude Code session inside emdash
2. Start a new Claude Code session in emdash
3. Observe the bottom statusLine — the multi-line HUD output from claude-hud is missing or broken
4. Click away to another panel or app, then look back at the terminal — the statusLine may now appear

Actual vs Expected Behavior

Actual: The statusLine is missing or renders at the wrong position, causing it to be invisible or to flicker. The behaviour is inconsistent: sometimes the correct content appears briefly, then gets overwritten.

Expected: The statusLine renders correctly at the bottom of the Claude Code TUI at all times, just as it does when running claude directly in a terminal emulator.

Root causes identified (both now fixed in PR):

1. CLAUDE_CONFIG_DIR not forwarded to the subprocess. CLAUDE_CONFIG_DIR was not in AGENT_ENV_VARS, so a custom config dir (containing plugins like claude-hud) was silently dropped when emdash spawned Claude Code via direct PTY. Additionally, Electron GUI apps on macOS don't inherit shell profile env vars, so CLAUDE_CONFIG_DIR set in ~/.zshrc was never picked up by the main process either.

2. Startup SIGWINCH desynchronises React Ink's statusLine line-counter. The PTY was spawned with a hardcoded fallback size of 120×32. fitAddon.fit() ran asynchronously one animation frame later with the actual container dimensions (e.g. 180×42), sending a SIGWINCH to Claude Code immediately after startup. Claude Code's React Ink TUI tracks how many statusLine rows it rendered in a counter ($); the SIGWINCH reset the layout mid-render, desynchronising this counter so the clear-and-redraw step (\x1B[${$}A\x1B[J) operated on the wrong number of lines, pushing the statusLine outside the visible viewport.

emdash Version

0.4.45

Operating System

macOS 25.4.0 (Darwin)

Additional Context