evil_MoE/.claude/memory/bash-tool-shell-gotchas.md

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name: bash-tool-shell-gotchas description: Bash-tool zsh has noclobber ON; pi --mode json hangs on stdin (fix: </dev/null); workarounds metadata: node_type: memory type: feedback originSessionId: ba4a4349-3947-4bfe-87fc-2d6e99001352

The Bash tool runs a zsh where noclobber is ON, and it is NOT set in any user rc file (~/.zshrc, ~/.zshenv, etc. — grep finds nothing). So the harness/wrapper sets it; editing ~/.zshrc does NOT turn it off. Symptom: cmd > existing_file fails with file exists: <path> and writes 0 bytes.

Two recurring consequences and fixes:

1. pi --mode json HANGS waiting on stdin in the Bash tool (exit 124 on timeout, 0 bytes, even on a fast valid model; text mode works fine). The earlier "writes to tty" diagnosis was wrong. Real fix: redirect </dev/null so pi sees EOF on stdin and runs non-interactively. Full working recipe (external-review skill + the one missing bit): pi --model openrouter/<slug> --no-tools --no-skills -nc --system-prompt "$SYS" -p "$P" --mode json </dev/null | jq -j --unbuffered 'select(.type=="message_update" and .assistantMessageEvent.type=="text_delta") | .assistantMessageEvent.delta' | tee out.md tee is correct (skill uses it); do NOT pkill -f (kills the launching shell). Slugs: verify with pi --list-models | grep ^openrouter — a bad slug ALSO hangs silently. panel_direct.py (HTTP direct, reads /root/.env) stays a fallback but </dev/null makes plain pi work.

2. noclobber refuses > onto existing files. Use >| to force-overwrite, or rm -f first, or have the program write the file itself (Python Path.write_text, tee both work; > redirect does not).

Why: wasted ~an hour chasing 0-byte panel output that looked like an auth/model problem but was noclobber + pi-tty. How to apply: when a > redirect or a piped CLI returns 0 bytes, suspect these two before debugging the tool itself.

Also: batching many Bash calls in one message causes cascade-cancellation — if the first errors (e.g. the noclobber test exits 2), the rest are all cancelled. Run diagnostics sequentially. See projected-grpo-rebuild-from-pseudocode.