I think self.pattern needs to be changed into self.path_as_pattern:
I run into the issue with a simple
sources:
2D_const_0.25deg:
description: 2D constant variables from IFS-AMIP
driver: netcdf
args:
urlpath: "/work/bk1377/b382473/IFS_AMIP/prepIFS/OSTIA/gribscan/2D_const_0.25deg/*.grib"
xarray_kwargs:
engine: cfgrib
catalog.