Error in FORTRAN subroutine ARCINT

[arbenede]

I am trying to interpolate data on the sphere using a custom triangulation with interpolate_to_grid() and I am getting this error:

1ERROR IN ARCINT -- P1 =  0.755685,  -0.650065,   0.079723
                    P2 =  0.755240,  -0.650605,   0.079533

I traced it to SUBROUTINE ARCINT (P,P1,P2,F1,F2,G1,G2,SIGMA, F,G,GN) in ssrfpack.f90. The problem is that P1 and P2 are parallel. I am wondering if there is away to circumvent this error by "fixing" my triangulation in some way also since the last time I wrote FORTRAN code was in the 80's... I'm willing to help debug this and make a PR of course.