Single Error Label Masked Three Distinct Failures in AI Model Test Harness

A developer discovered that a test harness reducer was returning the same error code, EXEC_ARGUMENTS_MISMATCH, across three genuinely different failure scenarios. The original code used a single try-catch block that routed parse failures, argument mismatches, and comparator errors all under one label, making it impossible to distinguish what actually went wrong. The fix split the logic into separate try-catch blocks, assigning distinct codes — EXEC_ARGUMENTS_INVALID and EXEC_COMPARATOR_ERROR — to each failure stage. The change, spanning three source files and associated tests, was described by contributor pm25coder as a rename rather than a redesign. While the labels were not technically incorrect, their ambiguity silently obscured which of the three failure types had actually occurred.