Coding agents fix bugs where the error shows up, not where it starts

Coding agents often fix bugs at the point of error manifestation, rather than addressing the root cause. This typically involves adding null checks, default values, try/except blocks, or early returns where an error is thrown. While this resolves the immediate issue and allows tests to pass, the underlying problem that generates the bad value upstream remains unaddressed, merely being silently handled instead of causing a loud failure.

This report highlights a critical limitation of current coding agents, showing they often patch symptoms rather than fixing root causes, unlike traditional debugging that seeks upstream origins.