Any chance you can trigger this crash using a script that relies on a
public dataset? I'm happy to debug, but need to be able to reproduce this
locally to see what's going wrong.
Nathan
On Tuesday, August 4, 2015, Brian O'Shea
Hi folks,
I have been trying to make some dark matter density movies using the "all_cic" field, and have discovered that using "all_cic" can reliably cause yt to seg fault on the supercomputer I'm using (x86_64 linux cluster with kernel 2.6.32-504.8.1.el6.x86_64) using the tip of yt-dev (changeset fa08e386d0da). The script that causes the crash is here:
http://paste.yt-project.org/show/5774/
After I turned up the log level and started using pdb to debug, I discovered that the line in the script that causes the seg fault is line 88:
dm_dens_x = my_reg[("deposit", "all_cic")].value
where my_reg is defined as (on line 82):
my_reg = ds.arbitrary_grid(left, right, dims=[1,800, 800])
After stepping through with pdb, it seems that the code dies in this function:
/mnt/home/oshea/yt-3/lib/python2.7/site-packages/sympy/core/basic.py(83)__new__()
with the traceback shown here:
http://paste.yt-project.org/show/5775/
Based on this traceback, it seems that there are problems with the unit system.
Interestingly enough, though, this does not happen on every dataset - it seems to happen occasionally, but predictably. For example, I can generate two images using this script, but it will seg fault on the third. On a different dataset in the time series, it will produce one image and then seg fault on the second. If I run the script over and over, it will eventually produce quite a few images, until it runs into a situation where it seg faults on the first image I produce (at which point I went to the debugger).
I don't have enough experience with the guts of yt - and the units section of yt in particular - to have a sense of what might be happening here based on the traceback. Does anybody have any suggestions?
Thank you!
--Brian