running bubble 3D test results in segafault

[fcannini]

Hi Ethan, how are you?

I've got back to the bubble_3D test problem of #1 and can't move forward.
All other tests run just fine.
............................................................................................................
[user@machine bubble_3D]$ gdb --args ./runSimulation input_data
...
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib64/libthread_db.so.1".
[New Thread 0x7fffe9c9c700 (LWP 13601)]
Scale report from LBM:
length scale [m]: 1.00000000000000
time scale [s]: 1.00000000000000
velocity scale [m/s]: 1.00000000000000
mass scale [kg]: 1.00000000000000
bubble format: 54 74 54 74 calling lbm from inital step 0 to final step 100
outputing step 0 to file 0

Program received signal SIGSEGV, Segmentation fault.
0x0000000000775395 in lbm_forcing_module::lbmaddfluidfluidforcesd3 (dist=..., components=..., rho=..., walls=..., forces=...) at lbm_forcing.F90:71
71 gradrho = 0.
............................................................................................................

It's weird that the code would segfault in that part, but I'm by no means knowledgeable in fortran. Any idea why is it happening?

TIA,
Fabricio