3.14 GFORTRAN_ERROR_BACKTRACE—Show backtrace on run-time errors

If the GFORTRAN_ERROR_BACKTRACE variable is set to `y', `Y' or `1' (only the first letter is relevant) then a backtrace is printed when a run-time error occurs. To disable the backtracing, set the variable to `n', `N', `0'. Default is not to print a backtrace unless the -fbacktrace compile option was used.