fix(orch): lower inline-prompt cap below tmux's command-length limit#61
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A reviewer session failed to launch with 'command too long': its ~17KB opening prompt was passed inline as a tmux/SSH command argument and blew tmux's command-length cap. The externalize-to-file threshold was 32KB — set against the kernel's ~128KB MAX_ARG_STRLEN — but that's the wrong limit: tmux's own cap is far lower. Measured on the prod SSH box, a remote 'tmux new-session' starts failing between 12KB and 16KB of total command, so a 17KB prompt sailed under 32KB and straight into the failure. Lower maxInlinePromptBytes to 8KB so the assembled command (agent flags + the --mcp-config JSON + the prompt) stays well under tmux's cap; larger prompts are written to a file and replaced by a short bootstrap, exactly as before — just triggered at a safe size now. Managers ran fine inline because their prompts sat under tmux's limit; large reviewer/follow-up prompts (which carry a diff) are the ones that cross it, and those now externalize.
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Bug (prod)
A reviewer session failed to start:
The opening prompt (~17KB: a reviewer's preamble + the diff to review) was passed inline as a tmux command argument and blew tmux's command-length cap.
Why the existing guard missed it
orcha already moves oversized prompts to a file (
externalizeLargePrompt), but the threshold was 32KB, chosen against the kernel's ~128KBMAX_ARG_STRLEN. That's the wrong limit — the binding constraint is tmux's own command-length cap, which is far lower. Measured on the prod SSH box:So tmux caps out ~12–16 KB, and a 17 KB prompt sailed under the 32 KB threshold straight into the failure.
Fix
Lower
maxInlinePromptBytesto 8 KB. The assembled command (agent flags + the--mcp-configJSON + the prompt) then stays well clear of tmux's cap; anything larger is written to a file and replaced by a short bootstrap (cat <path>to read it) — the exact mechanism that already existed, just triggered at a safe size.Managers were fine inline because their prompts sit under tmux's limit; it's the large reviewer/follow-up prompts (which carry a diff) that cross it, and those now externalize. Covered by the existing
TestExternalizeLargePrompt_OffloadsToFileWhenBig(usesmaxInlinePromptBytes+1, so it tracks the new value). Full suite + vet green.Open PRs now
#60 (submodule skip) and this one.