Passing input files to output channels without storing duplicates

input_file_passing.nf

#!/usr/bin/env nextflow

in_ch = Channel.from(file("test.txt"))

process test {
    storeDir 'out/1'
    stageInMode 'rellink'
    stageOutMode 'move'
    
    input:
    file x from in_ch

    output:
    set(file("out.txt"), val(x)) into out_ch

    shell:
    '''
    echo "hi" > out.txt
    '''
}

process test2 {
    storeDir 'out/2'
    stageInMode 'rellink'
    stageOutMode 'move'

    input:
    set(file(a), file(b)) from out_ch

    output:
    set(val(a), val(b), file("new.txt")) into out2_ch

    shell:
    '''
    cat !{a} !{b} > new.txt
    '''
}

out2_ch.subscribe { println(it) }