In one embodiment, a computer system determines that a previously run test scenario configured to test a software program has failed to produce an expected result due to one or more semantic errors, generates error trace code configured to monitor the called component, processes the test scenario using the error trace code, and analyzes error trace information to determine the point at which the semantic error occurs in the called component. In an alternative embodiment, a computer system detects a semantic error in a software component of a software program, constructs an error condition that may include source code representing a minimum condition under which the error occurs, generates an object invariant based on the error condition that represents an opposite condition to that represented by the error condition, and automatically generates source code change recommendations using the object invariant that prevent the semantic error from reoccurring in subsequent test scenarios.