See the attached sample problem. In Debug.cfg, add the line:

:Solver

Running the problem results in a seg fault due to a failed attempt to output some internal data because a transaction on the stack is deleted due to relaxations etc going on elsewhere.

Attached is a trail of email discussion involving the bug (the 'Debug' message describes the details of what is going on while the other 7 are a discussion amongst us as to how this should be handled).

Mike believes that the fix for issue 62 also solved this one. Note that there is also issue 64 which is related. Anyway, we will close this instance of the problem.