TRUFFLE segmentation fault when using --pair option

Hello,
I am trying to use TRUFFLE to find pairwise IBD segments.  The software fails to finish with the --pair option (using sample IDs from multi-sample VCF input to specify pairs).  The program completes successfully on the same input VCF when the --pair option is not specified, here is the output of the failed command:


[*]  Finished reading input files:  1449645.07 ms



     -   Expected IBS for unrelated pairs: p.IBS0 = 0.0660  p.IBS1 = 0.4274  p.IBS2 = 0.5067

     -   Likelihood based region estimate: 1340 p=7.99196e-11

(ibs_est)       -   549 p=0.934037 perr=0.000000

(ibs_est)       -   56 p=0.506675 perr=0.000000

(ibs_est) Thresholds for defining regions as IBD1 = 549, IBD2 = 56

(ibs_est) Inflation at edges IBS1 = 28.3, IBS2 = 1.9

     -   Genome size: 14545555.294000

     -   gs_threshold=41057.644051

     -   (ibs_est) Adjust segment size to 41057 markers (from 549)

     -   IBS1 threshold : 0.08 % of genome  (41057 markers)

     -   IBS2 threshold : 0.01 % of genome  (6842 markers)







[*]  Starting IBD segment loop

     -   Allocation genotype vector transposed npeople=18 nvars=54564296

     -   GenotypeMatrixTransposed: allocating 936 MB of memory





[*]  Genotype pre-processing duration:  1504475.52 ms



-  Compute IBD by IBS: (cpu=1/1) Nind = 17 Nvar = 54564296

Running pair -1 -1

Segmentation fault

 


Any idea why this is failing, or how to fix?
Thanks,
Brook