Building LineageOS for discontinued device: where are all the manifest xml's??

It all goes well until brunch, when I get tons of errors about missing manifest xml's. I can browse to the folder where the xml file should be (the folder exists) but the folder is empty. Where am I supposed to get them??

EDIT: to be clear, this device has been dropped from LOS support. I have an installation zip and got the proprietary blobs tho...