POSIX xargs Apostrophe Failure Silently Erases Feature Detection #14

Summary

_detect_features_fast feeds a newline-separated file list into xargs grep without -d '\n' or -0. If any file in the target repository has an apostrophe or single quote in its path (e.g. src/don't_crash.js), xargs fails with unmatched single quote and outputs nothing. The recon step silently detects 0 features.

Root Cause

In openhack/deterministic_recon.py:182-190:

cmd = ["xargs", "grep", "-Fl", "--max-count=1", "--binary-files=without-match"]
proc = subprocess.run(cmd, input=file_list, capture_output=True, text=True, timeout=15)

POSIX xargs treats single quotes as quoting characters by default.

Reproduction

touch "don't_break.js"
# xargs grep fails with returncode=1, stderr="xargs: unmatched single quote", stdout=""

Impact

A single apostrophe anywhere in the target repository's filenames completely blacks out deterministic feature detection for all categories.

Proposed Fix

Pass -d '\n' to xargs:

cmd = ["xargs", "-d", "\n", "grep", "-Fl", "--max-count=1", "--binary-files=without-match"]