Update 2:

I replaced stable with jessie as follows. debootstrap did better but
failed. These are the results:

# debootstrap --arch amd64 jessie /mnt/sda8 http://packages.devuan.org/devuan/
W: Cannot check Release signature; keyring file not available
/usr/share/keyrings/devuan-keyring.gpg
I: Retrieving Release
I: Validating Packages
I: Resolving dependencies of required packages...
I: Resolving dependencies of base packages...
I: Checking component main on http://packages.devuan.org/devuan...
I: Validating devuan-keyring 2015.04.11
I: Validating bsdutils 1:2.25.2-4.1+devuan1
I: Validating libblkid1 2.25.2-4.1+devuan1
I: Validating libmount1 2.25.2-4.1+devuan1
I: Validating libsmartcols1 2.25.2-4.1+devuan1
I: Validating libuuid1 2.25.2-4.1+devuan1
I: Validating mount 2.25.2-4.1+devuan1
I: Validating util-linux 2.25.2-4.1+devuan1
I: Chosen extractor for .deb packages: dpkg-deb
I: Extracting bsdutils...
I: Extracting libblkid1...
I: Extracting libmount1...
I: Extracting libsmartcols1...
I: Extracting libuuid1...
I: Extracting mount...
I: Extracting util-linux...
W: Failure trying to run: chroot /mnt/sda8 mount -t proc proc /proc
W: See /mnt/sda8/debootstrap/debootstrap.log for details


Contents of debootstrap.log:

gpgv: Signature made Sat Apr 25 18:26:22 2015 UTC using RSA key ID 541922FB
gpgv: Can't check signature: public key not found
gpgv: Signature made Sat Apr 25 18:26:22 2015 UTC using RSA key ID 541922FB
gpgv: Can't check signature: public key not found
gpgv: Signature made Sat Apr 25 18:26:22 2015 UTC using RSA key ID 541922FB
gpgv: Can't check signature: public key not found
gpgv: Signature made Sat Apr 25 18:26:22 2015 UTC using RSA key ID 541922FB
gpgv: Can't check signature: public key not found
dpkg-deb: error: error reading archive magic version number from file
/mnt/sda8/: Is a directory
chroot: failed to run command 'mount': No such file or directory
dpkg-deb: error: error reading archive magic version number from file
/mnt/sda8/: Is a directory
chroot: failed to run command 'mount': No such file or directory


On 29/04/2015, Edward Bartolo <edbarx@???> wrote:
> 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.
>