Unable to compute Kruskal-Wallis with feature humann2_associate

Hi! We are trying to use the command humann2_associate, and our output files are empty besides the first line. Our error file says only the following:

NOTE: Unable to compute Kruskal-Wallis with feature: VALSYN-PWY: L-valine biosynthesis
Performing Kruskal-Wallis analysis vs. metadatum: STATUS
Finished successfully.

There should be significant associations given the amount of data. Why is this not working? Is there a reason why it is unable to perform the test?

humann2_associate is mostly included with HUMAnN2 for demo purposes. I’d recommend trying out MaAsLin2 for more formal analyses.

That said, if you’re able to share some/all of the table that gives rise to this error, I can take a look at it.