It's not possible AFAICT to configure snapcraft to download snaps from a brand store with build-snaps or stage-snaps. Poking around at the source, it looks like snapcraft is downloading snaps with this function: https://github.com/snapcore/snapcraft/blob/master/snapcraft/internal/repo/snaps.py#L163-L175 which if I run `snap download` outside of snapcraft I am able to download snaps from my brand store by specifying the env vars: UBUNTU_STORE_AUTH_DATA_FILENAME=./creds UBUNTU_STORE_ID=my-cool-brand-store-id snap download my-cool-brand-store-snap --edge (where creds is from snapcraft export-login) Attempting to provide this env vars to snapcraft doesn't seem to propogate them to the snap download command that snapcraft runs. I.e. this fails: UBUNTU_STORE_AUTH_DATA_FILENAME=./creds UBUNTU_STORE_ID=my-cool-brand-store-id snapcraft It also fails in destructive-mode: UBUNTU_STORE_AUTH_DATA_FILENAME=./creds UBUNTU_STORE_ID=my-cool-brand-store-id snapcraft --destructive-mode