Error when trying to move multiple file types in wdl

Question

I tried to add a "gather_results" task to a workflow that takes in an array of Files and moves output files to a new folder of a specified name.

Cannot interpolate Array[File?]+ into a command string with attribute set wdl PlaceholderAttributeSet(None,None,None,Some( ))]

The wdl file passes womtools and I have no idea what a PlaceholderAttributeSet is, which makes debugging quite difficult.

--

gather files task

task gather_result{
  input{
    String dir
    String? subDir
    Array[File?]+ files
  }

  command
  {
    mkdir --parents ${dir}/${default="" subDir}; /bin/mv -t ${dir}/${default="" subDir} ${sep=" " files}
  }
  runtime
  {
    docker_image: "pipeline"
    memory: "2 GB"
  }
  output
  {
    String out = stdout()
  }
}

How it's called:

  call gather_result as gather_files {
      input: files=[create_hic.output_hic[1],
                    dedup.deduped_bam,
                    calculate_stats.stats[0],
                    calculate_stats.stats_hists[0],
                    calculate_stats.stats_json[0]],
            dir=OutputDir
    }

Answer 1

I think you'll need to convert your Array[File?]+ to a Array[File] before you can use ~{sep=" " files} in the command section.

You can use the select_all function for that, which will only keep valid files.

https://github.com/openwdl/wdl/blob/main/versions/development/SPEC.md#arrayx-select_allarrayx