Description of problem:
I have an existing MD device which contains LUKS data inside.

I clicked the unlock icon on the LUKS formatted MD device. This caused an error.

It seems that blivet doesn't start the existing MD array before it tries to decrypt it and thus raises an error because the MD device does not exist.

Version-Release number of selected component:
anaconda-31.22.6

The following was filed automatically by anaconda:
anaconda 31.22.6 exception report
Traceback (most recent call first):
  File "/usr/lib/python3.7/site-packages/blivet/formats/__init__.py", line 630, in _pre_setup
    raise FormatSetupError("invalid device specification")
  File "/usr/lib/python3.7/site-packages/blivet/threads.py", line 53, in run_with_lock
    return m(*args, **kwargs)
  File "/usr/lib/python3.7/site-packages/blivet/formats/luks.py", line 251, in _pre_setup
    return super(LUKS, self)._pre_setup(**kwargs)
  File "/usr/lib/python3.7/site-packages/blivet/threads.py", line 53, in run_with_lock
    return m(*args, **kwargs)
  File "/usr/lib/python3.7/site-packages/blivet/formats/__init__.py", line 603, in setup
    if not self._pre_setup(**kwargs):
  File "/usr/lib/python3.7/site-packages/blivet/threads.py", line 53, in run_with_lock
    return m(*args, **kwargs)
  File "/usr/lib/python3.7/site-packages/blivetgui/blivet_utils.py", line 1367, in luks_decrypt
    blivet_device.format.setup()
  File "/usr/lib/python3.7/site-packages/blivetgui/osinstall.py", line 80, in remote_call
    return utils_method(*args)
  File "/usr/lib/python3.7/site-packages/blivetgui/blivetgui.py", line 651, in decrypt_device
    ret = self.client.remote_call("luks_decrypt", self.list_partitions.selected_partition[0], response)
blivet.errors.FormatSetupError: invalid device specification

Additional info:
addons:         com_redhat_kdump
cmdline:        /usr/bin/python3  /sbin/anaconda
cmdline_file:   BOOT_IMAGE=/images/pxeboot/vmlinuz inst.stage2=hd:LABEL=Fedora-S-dvd-x86_64-31 quiet
dnf.librepo.log: 
executable:     /sbin/anaconda
hashmarkername: anaconda
hawkey.log:     INFO Jan-03 07:52:56 === Started libdnf-0.35.3 ===
kernel:         5.3.7-301.fc31.x86_64
product:        Fedora
release:        Fedora release 31 (Thirty One)
type:           anaconda
version:        31

Potential duplicate: bug 1476544