Legion: uninitialized data error

[syamajala]

I'm seeing the following error in S3D:

[0 - 1554c806a000]   93.994331 {5}{runtime}: [error 68] LEGION ERROR: Region requirement 5 of operation HandoffToMPITask (UID 107293, provenance: s3d.rg:2607) in parent task main (UID 2) is using uninitialized data for field(s) 101,102 of logical region (44,14,14) with read-only privileges (from file /lustre/scratch/vsyamaj/legion_s3d_tdb/legion/runtime/legion/legion_ops.cc:1748)
For more information see:
http://legion.stanford.edu/messages/error_code.html#error_code_68

The handoff task is taking a rank level partition and there is a fill on the subrank level partition for this region, there are also leaf tasks with read write privileges on those fields that execute fine before the handoff task, so the handoff task should work. I was able to work around this error by adding a rank level fill, but that should not be necessary.

I will try to find a reproducer for this.

[lightsighter]

If you're detaching then that will set the region state back to "uninitialized". I would be very surprised if Legion is incorrect in its diagnosis about doing an uninitialized read.