create an empty alignment file if none could be produced by the snakemake rules.
create an empty alignment file if none could be produced by the snakemake rules.

EichlerLab/pacbio_variant_caller,EichlerLab/pacbio_variant_caller,EichlerLab/pacbio_variant_caller,EichlerLab/pacbio_variant_caller,EichlerLab/pacbio_variant_caller