1. A method for gathering diagnostics during a transactional execution in a transactional memory environment for performing transactional executions, wherein memory store data of a transaction are committed to memory after transaction completion, the method comprising: identifying, by a computer system, a beginning instruction of a transaction, the transaction comprising a plurality of instructions; identifying, by the computer system, an ending instruction of the transaction; generating, by the computer system, a computed digest based on a digest generating algorithm operating on invariant data in one or more executed instruction of the transaction; accumulating, by the computer system, diagnostic data of the transaction based on the executed instructions of the transaction, wherein the diagnostic data includes the computed digest and one or more of: a list of instructions used in the generation of the computed digest; a transaction progress indicator; a list of transactional execution memory addresses; an instruction that encountered an execution failure; and a reason for the execution failure; and upon completion of the transaction, determining whether the computed digest matches a previously saved computed digest that is based on the digest generating algorithm operating on the invariant data in a previous completion of the transaction; based on the computed digest not matching the previously saved computed digest: aborting of the transaction; saving, by the computer system, the diagnostic data; and not saving the memory store data of the transaction to memory.