Conservative regridding from rotated pole to OSGB grid

Hi,

I'm trying to carry out conservative regridding of a netcdf from the EuroCordex rotated-pole grid onto a regular OSGB grid (although at this point, I'd settle for a regular lat-lon grid). Linear interpolation works fine, but when I try to carry out conservative regridding, I get an error message: Source <CF AuxiliaryCoordinate: longitude(412, 424) degrees_east> coordinates must have contiguous, non-overlapping bounds for conservative regridding.

The auxiliary coordinates are 2d arrays of latitude & longitude, while the dimension coordinates are 1d vectors of rotated latitude and rotated longitude. The auxiliary coordinates do have bounds in the original .nc file - I've checked using R and each bounded quadrilateral shares two vertices with each neighbour, suggesting that they define contiguous, non-overlapping regions. I've tried setting and resetting the bounds of the main dimension coordinates in both the source and grid files, but haven't been able to reset the bounds of the auxiliary coordinates that seem to be causing the problem. Can you advise the best way to resolve this issue to allow conservative regridding of rotated-pole data onto a regular OSGB grid?

(details of source data here, details of target grid here)

Thanks,
Clair

Start by comparing the attached nc-dump.txt source metadata with grid-dump.txt, focusing on the auxiliary longitude and latitude bounds used by conservative regridding. Trace the conservative regridding entry point that validates contiguous, non-overlapping bounds; done means rotated-pole data can be conservatively regridded without that validation error.