#No preliminary seqid/taxid mapping files found, aborting.

[SamridhiVerma07]

Hi everyone

I'm writing this here in hope that someone will solve this issue as this is already an unsolved issue as per the thread, #291

So, I faced this issue while creating custom database for bacteria (installed per the instructions here https://github.com/DerrickWood/kraken2/wiki/Manual#standard-kraken-2-database with these commands:

kraken2-build --download-taxonomy --db $DBNAME

kraken2-build --download-library bacteria --db $DBNAME

the above command kraken2-build --download-library bacteria --db $DBNAME gave:

rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1865) [generator=3.2.7]
rsync_from_ncbi.pl: rsync error, exiting: 5888

after which the build command,
kraken2-build --build --db $DBNAME

again encountered error:
No preliminary seqid/taxid mapping files found, aborting."

I don't know how to solve this. Please help

[ChillarAnand]

If the download command gave an error, you need to retry the download and then try build. @SamridhiVerma07

[jenniferlu717]

The library did not download, but im not 100% about what caused the download to fail. You will need to redownload or download manually or use krakenuniq-download