Timing of output format error indication

[AsagaKosho]

I ran diamond with -f 6 qseqid sseqid pident length evalue bitscore sacc salltitles staxids sscinames scomnames sskingdoms option. Then, I encountered the following error after most of the analysis had been completed.

Joining output blocks... Joining output blocks... Error: Invalid output field: sacc
Error: Invalid output field: sacc

Would you consider displaying this error before execution?

[bbuchfink]

Yes that's probably a good idea.

[clf-bio]

Why doesn't Diamond support sacc in outfmt？