---
id: "bug-1616"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "build"
severity: "unknown"
timestamp: "2026-08-21T00:00:00Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 1
files: ["src/tools/test-dirty-fingerprint-nix-production-path.sh"]
tags: ["bash", "set-u", "local", "unbound-variable", "dirty-content-fingerprint", "task-6.3", "src/tools", "recurring-pattern"]
related: ["bug-1615"]
legacy: true
---

# bug-1616: src/tools/test-dirty-fingerprint-nix-production-path.sh: line 191: flag: unbound variable

## Description
src/tools/test-dirty-fingerprint-nix-production-path.sh: line 191: flag: unbound variable

## Environment
_Not recorded (migrated from buglog.json)._

## Reproduction
_Not recorded (migrated from buglog.json)._

## Root cause
extract_flag_from_json()'s `local json="$1" flag="$2" needle="-D${flag}="` recurred the exact same-statement `local` cross-reference gotcha already documented as bug-1615 (test-dirty-fingerprint-distinguishability.sh's capture_version()): bash expands every word of a single `local` command before any of that command's own assignments take effect, so `${flag}` in the third word's value expanded against the not-yet-declared `flag`, an unbound-variable error under `set -u`.

## Fix
Split into two separate `local` statements (`local json="$1" flag="$2"` then `local needle="-D${flag}="` on its own line), with an inline comment citing bug-1615 explicitly so a future reader recognizes the pattern immediately instead of re-discovering it. Confirmed via `bash -n` plus a full real end-to-end script run (exit 0).

## Verification
_Not recorded (migrated from buglog.json)._

## References
- Related: bug-1615