I'm using grub 2.12 with GRUB_ENABLE_CRYPTODISK=y in /etc/default/grub. My /boot partition is encrypted with luks2.

If install grub with the following command:

 $ grub-install --boot-directory=/boot --efi-directory=/boot/efi --target=x86_64-efi /dev/nvme0n1

I'm unable to boot my system. The problem is that I'm using 512 bit key, while grub-mkimage is not installing gcry_sha512:

grub-mkimage --directory '/usr/lib/grub/x86_64-efi' --prefix '' --output '/boot/grub/x86_64-efi/grub.efi' --format 'x86_64-efi' --compression 'auto' --config '/boot/grub/x86_64-efi/load.cfg' 'btrfs' 'cryptodisk' 'luks2' 'gcry_rijndael' 'gcry_rijndael' 'gcry_sha256' 'part_gpt'

To fix this problem I've used --modules option:

 $ grub-install --boot-directory=/boot --efi-directory=/boot/efi --target=x86_64-efi --modules=gcry_sha512 /dev/nvme0n1

Yet I think autodetection is needed here. That's why this bug report.

BTW, thanks for improving luks2 support in grub! This work is really appreciated!

========================================================
x1 ~ # cryptsetup luksDump /dev/nvme0n1p2
LUKS header information
Version:       2
Epoch:         12
Metadata area: 16384 [bytes]
Keyslots area: 16744448 [bytes]
UUID:          78a0d770-9d7a-49ed-b361-d13b1cba9db8
Label:         (no label)
Subsystem:     (no subsystem)
Flags:       (no flags)

Data segments:
  0: crypt
offset: 16777216 [bytes]
length: (whole device)
cipher: aes-xts-plain64
sector: 512 [bytes]

Keyslots:
  0: luks2
Key:        512 bits
Priority:   normal
Cipher:     aes-xts-plain64
Cipher key: 512 bits
PBKDF:      argon2i
Time cost:  7
Memory:     1048576
Threads:    4
Salt:       ff 5f 21 e2 11 18 83 6a 24 84 64 ac 6c 62 4d dc
            87 50 66 8f c5 3a 14 e9 6c 59 37 63 07 15 71 e1
AF stripes: 4000
AF hash:    sha256
Area offset:32768 [bytes]
Area length:258048 [bytes]
Digest ID:  0
  1: luks2
Key:        512 bits
Priority:   normal
Cipher:     aes-xts-plain64
Cipher key: 512 bits
PBKDF:      pbkdf2
Hash:       sha512
Iterations: 3371626
Salt:       c0 42 9c 79 85 1a 20 ac 62 88 28 08 e2 84 67 16
            af cf 64 d2 47 ce f7 83 ff 96 c6 68 a8 90 56 19
AF stripes: 4000
AF hash:    sha512
Area offset:290816 [bytes]
Area length:258048 [bytes]
Digest ID:  0
Tokens:
Digests:
  0: pbkdf2
Hash:       sha256
Iterations: 151353
Salt:       9c bd db 3e d7 69 33 78 85 a3 da 6e ce 55 f7 ab
            7f 50 71 ee 82 b6 1a 13 63 f5 73 a7 86 b5 c9 b7
Digest:     70 51 98 d3 5e b9 ad 21 4a fa c2 52 be 75 2d 03
            e8 99 d7 95 2a 55 67 38 15 e8 eb 92 5a 3e 54 29
========================================================