Johannes Buchner

something along those lines anyways, you will have to try around a bit

That should be dump_callback instead of dump_wrapper

(bug in https://github.com/JohannesBuchner/PyMultiNest/blob/master/pymultinest/run.py#L199 )

Try as a starting point ``` python def func(nsamples, nlive, n, postdist): print 'python dumper callback called!' sys.stdout.flush() print nsamples, nlive, n sys.stdout.flush() ```

In [the multinest bridge](https://github.com/JohannesBuchner/PyMultiNest/blob/master/multinest_bridge/cnest.c) try simplifying ``` #define DUMPERTYPE(f) void (f)(int nsamples, int nlive, int npar, \ double ** physlive, double ** posterior, \ double *mean, double *std, double *best,...

Try putting a few printf in before the p.Dumper() call to check whether *nsamples, *nlive, n, and postdist contain reasonable values (e.g. not NULL). You can also try replacing ```...

You can check by replacing postdist in the p.Dumper call by NULL for the moment. printf("%p\n", postdist) would tell you the address.

Hi @tfish13, thank you for reporting the issue. It seems to me that the problem occurs at the moment MultiNest exits. Perhaps MPI is terminated twice?

Dear tfish, I was wondering if you still have this problem. I have now released an update to PyMultiNest, which includes some MPI-related fixes (setting init_MPI to False by default)....

Please reopen if the problems still exist. You need to install mpi4py to use MPI functionality.