Status codes

The codeDescription
0 Success, results are both reliable and accurate
1 Success, results are reliable, can be inaccurate due rounding
2 Success, a basic estimate for a single point or a pair
3 Success, majority of data looks identical.
5 Fail, improper input parameters (reltol, scale < 0, etc.)
6 Fail, no convergence or a unexpected error
8 Fail, failed to allocate a memory.

The status codes < 5 indicates the success, whilst ≥ 5 stands for a fail. Some subroutines use codes above ten for an inter-routine communication.

verbose = .true. is helpfull in doubts.