current=$(grep ...) ran before checking whether the key existed in .env at all. Under set -euo pipefail, a key missing from .env (e.g. a new tunable this branch just added to .env.example) made that grep exit 1, pipefail propagated it, and set -e killed the script instantly with no output - looked exactly like a gum hang but never reached ensure_gum. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Bs8xf8Dt8X6tRBvBiLCXYc