What does '-E'/evaluation mode do?

[Andy-B-123]

Hi, thank you for this tool and for your thorough and helpful documentation and examples!

I'm looking through the options and see the '-E' flag labelled as 'Run LiftOn in evaluation mode'.

When I try and run this with the examples (eg the HoneyBee one) it produces an error? eg:

lifton -g HAv3.1_genomic.gff -o lifton.gff3 -copies ASM1932182v1_genomic.fna HAv3.1_genomic.fna -E

proceeds to start running normally and then errors at:

>> Creating target database :  lifton.gff3
gffutils database build failed with lifton.gff3 cannot be found and does not appear to be a URL

Is 'Evaluation mode' more of a testing feature? Thanks!