I am using the Devuan patched debootstrap in Debian Testing.
debootstrap failed with the following message:

# debootstrap --arch amd64 stable /mnt/sda8 http://packages.devuan.org/devuan
I: Retrieving Release
I: Retrieving Release.gpg
I: Checking Release signature
E: Release signed by unknown key (key id 94532124541922FB)

Any helpful pointers are much appreciated.
Thanks.