Bug#901981: gpg request dirmngr package, but LiveCD don't contain it

[Strelok <strelkov355@gmail.com>]

Package: debian-live
Version: 9.4.0

LiveCD (debian-live-9.4.0-amd64-mate.iso) don't contain dirmngr
package, so gpg also don't work.

wget https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/SHA512SUMS
wget https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/SHA512SUMS.sign
gpg --verify SHA512SUMS.sign
Result
gpg:                using RSA key DF9B9C49EAA9298432589D76DA87E80D6294BE9B
gpg:                Can't check signature: No public key.

Ok, then I just get public key!
gpg --recv-keys DF9B9C49EAA9298432589D76DA87E80D6294BE9B
Result:
gpg: failed to start the dirmngr ’/usr/bin/dirmngr’: No such file or directory

Yes, yes, sudo apt-get install dirmngr. But I think this package must
by installed by default.