Multi-channel output cannot be applied to operator combine for which argument is already provided

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1

Hi can you please help me debug this issue. When trying to use the join operator:
samples_merged_frum = merge_fastqs_frum(filtered_fastq, params.subsample_seed)
samples_merged_nofrum = merge_fastqs_nofrum(files, params.subsample_seed)
samples_merged = samples_merged_frum.join(samples_merged_nofrum, by: [0,1])

I get this error:
Multi-channel output cannot be applied to operator join for which argument is already provided

2

Can you please provide us with a minimal reproducible example?

It seems to me samples_merged_frum or samples_merged_nofrum are multi-channels, that is, there are multiple channels within it. You have to tell Nextflow which one you’re trying to join with.