If installing from pip, please also download the source as it contains the demo examples.
But, it is already present on disk when installing using pip , so why download it again?
$ find software/* -name demo.fastq
software/Python3/lib/python3.7/site-packages/humann/tests/data/demo.fastq
Clicking the Code button and Download Zip downloads a 619 MB file which isn’t clear ahead of time. It might also be convenient to read that --install-option=--bypass-dependencies-install is mutually exclusive with a Demo Run.