Under set -u, "${arr[@]}" on an empty array aborts on bash before 4.4,
which is what macOS ships as /bin/bash. Three expansion sites now use
${arr[@]+"${arr[@]}"} consistently.
The hazard is not currently reachable: verified on a bash 3.2.57 built
from source that all seven invocation shapes succeed against the
previous code, including zero args, flags-only and an empty directory.
vale_args is provably non-empty at every site because the default
--config branch always appends first. The guard is kept because that
invariant is non-local and untested, so an edit to the default-config
branch would reintroduce a macOS-only crash silently.
Test fidelity is deliberately mixed. Case 16 is static and is the only
one that fails against the previous code, since no bash 5 host can
reproduce the abort at runtime. Case 17 runs the emptiest invocations
under the oldest bash it can find and names that shell in its output
so it cannot overclaim. Case 18 guards against the tempting wrong fix
of dropping the quotes, which also silences the abort but word-splits
a path containing a space.
No other bash 4.x construct is present; swept for mapfile, declare -A,
case modification, negative indices, globstar, wait -n and namerefs.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MCQ648fLSFXPHGZdQ8gn58
scripts/
Executable code bundled with this skill. Agents run scripts in this directory to perform repeatable operations rather than reinventing the logic each run.
When to add a script
Add a script when agents independently reinvent the same logic across runs — building the same parser, chart, or validation routine from scratch each time. Bundle it here once, tested and reliable.
Script requirements (agentskills.io)
Scripts must be designed for non-interactive, agentic execution:
- No interactive prompts — agents run in non-interactive shells. Accept all input via flags, env vars, or stdin. A script that blocks on TTY input hangs indefinitely.
- Expose
--help— this is how agents learn your script's interface. Keep the output concise; it enters the agent's context window. - Structured output — write data (JSON, CSV, TSV) to stdout. Write progress, warnings, and diagnostics to stderr.
- Idempotent — prefer "create if not exists" over "create and fail on duplicate". Agents may retry on failure.
- Meaningful exit codes —
0for success, non-zero for failure. Use distinct codes for different failure types; document them in--help. - Dry-run support — add
--dry-runfor destructive operations.
Self-contained scripts
Bundle dependencies inline so the agent can run the script with a single command.
Python (PEP 723 + uv):
# /// script
# dependencies = ["requests>=2.31,<3"]
# requires-python = ">=3.11"
# ///
import requests
uv run scripts/my-script.py
If no scripts are needed
Delete this README and the scripts/ directory entirely.