MCMCMC segfault with MPI

[ziad-khouri]

It appears that attempting to run an MCMCMC with MPI consistently results in a segmentation fault. MCMCMC appears to work without MPI, and I can run a regular MCMC with MPI with no issues.

I'm attaching a simple script that reproduces the error, as well the stdout and stderror when I attempt to run it.

Environment:
OS: Ubuntu 18.04
GCC: 8.3.0
OpenMPI: 4.0.1
RevBayes: 8eebff4
(development branch, Aug 23, 2019)

mc_cubed_test.zip

[ziad-khouri]

UPDATE:

I tested with an older version of revbayes (8c3100a) and could run mcmcmc with mpi with no obvious problems. Using the recent commit 9afdfe3 from Sept 11, 2019 results in a segfault.

I'm attaching a much simpler script (single exponentially distributed variable) that can be used to reproduce the issue.

@hoehna @mlandis

mcmcmc_test.zip

[jsigao]

I believe this commit (938d286) should have fixed the issue (at least the segfault disappears and the simple test case attached above seems to run fine).
@hoehna It would be great if you could have a look at it to see if I had fixed it right. Thanks!