A computer-implemented method, system and computer program product for generating test cases for testing software. Log files are analyzed for indications of software defects resulting in software errors. For those log files that were found to indicate software errors, such log files are analyzed to determine if they contain personal data that needs to be anonymized based on an entropy score of the personal data. When the entropy score of the personal data is below a threshold value, anonymized variations of the personal data are generated. Trace logs are then created containing the anonymized variations of the personal data, which are returned to a software tester to create a test case for testing software using the created trace logs without having access to personal data. In this manner, the software tester may reproduce the software errors without having access to the personal data.