Question 50
A coding subagent develops a suggested patch in an isolated worktree. While it works, the coordinator changes the same module on the main branch. The subagent returns a patch based on the older commit. What must happen before the coordinator applies it?
Explanation
Correct Answer
The child’s result is based on a particular commit and may conflict with work completed in the parent branch. Record that base, inspect the actual diff and changed paths, and merge or rebase using the current authorized branch as the integration target. Resolve any overlapping edits deliberately rather than by completion time. Then rerun applicable tests and review the exact merged artifact. Isolated development simplifies ownership; it does not provide automatic proof that two concurrent edits remain compatible.
Incorrect Answers
An isolated worktree protects the child from modifying the parent’s files while it develops its patch, but it does not make later integration conflict-free. The coordinator changed the target module after the child branched, so forcing an overwrite can erase authorized parent changes. A patch must be compared against its actual base and the current target. Reconciliation and testing are required before promoting work from one branch into another.
A wall-clock timestamp cannot show whether a patch includes a newer business rule, preserves all parent edits or even targets the correct revision. Clock skew and differing branch histories make last-finished-wins an unreliable merge policy. The coordinator must compare committed ancestry and changed content rather than trusting arrival time. An apparently recent child result can still overwrite a later parent edit unless its changes are reconciled against the target branch.
Tests on the child’s independent worktree establish behavior only for that child revision. Integration can introduce new code combinations or resolve a conflict incorrectly, and tests that passed before the merge may no longer cover the resulting code. The coordinator should preserve the child test evidence as useful input but must validate the integrated commit. Worktree isolation is not a substitute for post-merge correctness checks.



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