Env Merge Drops Nested Keys Debugging Lab

Env Merge Drops Nested KeysConfig & EnvironmentHardPreparing workspaceAutosaved

00:00

Incident Dossier

Env Merge Drops Nested Keys

The runtime combines a base config, a per-environment override, and an env map. The override sets a single nested key, but a shallow merge wipes the entire sibling group, and a downstream connection builder fails because the host it relied on was lost during the merge.

Initial failing signalenv override loses sibling key under same prefixExpected load({ db: { port: '5433' } }).db.host === 'prod.db' · received load({ db: { port: '5433' } }).db.host === undefined

Progress

1Reproduce the bugRun checks

2Edit the fixOpen

3Pass checksOpen

4Submit fixOpen

Reproduction Steps

Trace how the loader combines the base config with the env override.
Notice the merge step and how it combines two objects with a nested key.
Confirm that the sibling key under the same prefix is silently lost.
Make the smallest correction that preserves the sibling while honoring the override.

Focus Mode

Start

src/config.js
src/merge.js

Likely area

src/config.js
src/merge.js
src/load.js

Progressive hints

Hints reveal broad direction first, then narrow toward the suspect path without showing hidden tests or exact solution code.

TopicConfig & Environment

DifficultyHard

Est. time22 min

Workspacecreating

Explorer

Preparing workspace files…

Evidence Map

Failing signal loaded from challenge API
Workspace files loaded from workspace API
Results rendered only after API run/submit

Autosaved

workspace

Outputread-onlyready$ workspace boot

Workspace booting...