debootstrap --exclude systemd,systemd-sysv,libsystemd0 jessie .

without specifying a URL is working here (are the excludes needed?)

However after I chroot it and apt update:

W: GPG error: http://packages.devuan.org jessie InRelease: The following
signatures were invalid: BADSIG 94532124541922FB Devuan Repository
(Primary Devuan signing key) <repository@???>

"devuan-keyring" is installed.