In RHEL7 kvm host, running virt-customize/virt-sysprep command against a RHEL8 KVM image fails.

Issue

• In RHEL7 kvm host, running virt-customize/virt-sysprep command against a RHEL8 KVM image fails with the following error message.

$ sudo virt-customize -a rhel-8.0.qcow2 --root-password password:SomePassword12345!
virt-customize: warning: mount: mount exited with status 32: mount: wrong
fs type, bad option, bad superblock on /dev/sda1,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so. (ignored)
virt-customize: error: libguestfs error: is_dir: is_dir_stub: you must call
'mount' first to mount the root filesystem

If reporting bugs, run virt-customize with debugging enabled and include
the complete output:

  virt-customize -v -x [...]

# virt-sysprep -a <RHEL8 image>
[   0.0] Examining the guest ...
virt-sysprep: warning: mount_options: mount exited with status 32: mount:
wrong fs type, bad option, bad superblock on /dev/mapper/rhel-root,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so. (ignored)
virt-sysprep: warning: mount_options: mount: /boot: mount point is not a
directory (ignored)
[   2.8] Performing "abrt-data" ...
virt-sysprep: error: libguestfs error: glob_expand: glob_expand_stub: you
must call 'mount' first to mount the root filesystem

If reporting bugs, run virt-sysprep with debugging enabled and include the
complete output:

  virt-sysprep -v -x [...]