I'm slightly confused by the preprocessing workflow. The

meta.yml

says the following about the grouped entry.

- grouped_dna_fastas:
      type: file
      description: |
        Channel containing the prepared FASTA files for nucleotide sequences grouped into a singe list element.
        Structure: [ val(meta), path(fasta) ]
      pattern: "*{fasta,fna,fas,fa}"

Should the structure there actually be the below?

[ val(meta), [ fasta ] ]

Otherwise I don't understand the difference to the ungrouped output.

- ungrouped_dna:
      type: file
      description: |
        Channel containing each prepared FASTA file for nucleotide sequences as independent elements.
        Structure: [ val(meta), path(fasta) ]
      pattern: "*{fasta,fna,fas,fa}"

eagle eye

PR incoming...