'NBD' object has no attribute 'get_block_size'

[Playys228]

Version used
Provide output of virtnbdbackup -V
1.9.21

Describe the bug
I think this is an error that described also here with libnbd
#7

but there is not solve for this error.

Hypervisor information:
qemu-kvm
libvirt

Workaround:
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04.6 LTS"

logs:
sudo python3 virtnbdbackup -d win2k19 -l full -o /mnt/sdb/winServerBackups/
[2023-04-02 16:22:50] INFO lib common - printVersion [MainThread]: Version: 1.9.21 Arguments: virtnbdbackup -d win2k19 -l full -o /mnt/sdb/winServerBackups/
[2023-04-02 16:22:50] INFO root virtnbdbackup - main [MainThread]: Backup level: [full]
[2023-04-02 16:22:50] INFO root virtnbdbackup - main [MainThread]: Libvirt library version: [6000000]
[2023-04-02 16:22:50] INFO root disktype - Optical [MainThread]: Skipping attached [cdrom] device: [sdb].
[2023-04-02 16:22:50] INFO root disktype - Optical [MainThread]: Skipping attached [cdrom] device: [sdc].
[2023-04-02 16:22:50] INFO root virtnbdbackup - main [MainThread]: Backup will save [1] attached disks.
[2023-04-02 16:22:50] INFO root virtnbdbackup - main [MainThread]: Concurrent backup processes: [1]
[2023-04-02 16:22:50] INFO root checkpoint - redefine [MainThread]: Loading checkpoint list from: [/mnt/sdb/winServerBackups//checkpoints]
[2023-04-02 16:22:50] INFO root checkpoint - create [MainThread]: Checkpoint handling.
[2023-04-02 16:22:50] INFO root checkpoint - create [MainThread]: Removing all existent checkpoints before full backup.
[2023-04-02 16:22:50] INFO root checkpoint - create [MainThread]: Using checkpoint name: [virtnbdbackup.0].
[2023-04-02 16:22:50] INFO root virtnbdbackup - main [MainThread]: Local NDB Endpoint socket: [/var/tmp/virtnbdbackup.250465]
[2023-04-02 16:22:50] INFO root virtnbdbackup - main [MainThread]: Temporary scratch file target directory: [/var/tmp]
[2023-04-02 16:22:50] INFO root virtnbdbackup - startBackupJob [MainThread]: Starting backup job.
[2023-04-02 16:22:52] INFO fs fs - freeze [MainThread]: Freezed [3] filesystems.
[2023-04-02 16:22:52] INFO fs fs - thaw [MainThread]: Thawed [3] filesystems.
[2023-04-02 16:22:52] INFO root virtnbdbackup - main [MainThread]: Started backup job with checkpoint, saving information.
[2023-04-02 16:22:52] INFO root checkpoint - backup [MainThread]: Saving checkpoint config to: [/mnt/sdb/winServerBackups//checkpoints/virtnbdbackup.0.xml]
[2023-04-02 16:22:52] WARNING root checkpoint - getXml [MainThread]: Failed to get checkpoint info with size information: [unsupported flags (0x4) in function qemuCheckpointGetXMLDesc]
[2023-04-02 16:22:53] INFO nbd client - printVersion [sda]: libnbd version: 1.2.2
[2023-04-02 16:22:53] INFO nbd client - connect [sda]: Waiting until NBD server at [nbd+unix:///sda?socket=/var/tmp/virtnbdbackup.250465] is up.
[2023-04-02 16:22:54] CRITICAL root virtnbdbackup - main [MainThread]: Unknown Exception during backup: 'NBD' object has no attribute 'get_block_size'
[2023-04-02 16:22:54] ERROR root virtnbdbackup - main [MainThread]: 'NBD' object has no attribute 'get_block_size'
Traceback (most recent call last):
File "virtnbdbackup", line 526, in main
if future.result() is not True:
File "/usr/lib/python3.8/concurrent/futures/_base.py", line 437, in result
return self.__get_result()
File "/usr/lib/python3.8/concurrent/futures/_base.py", line 389, in __get_result
raise self._exception
File "/usr/lib/python3.8/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "virtnbdbackup", line 740, in backupDisk
connection = connectNbd(args, disk, metaContext, remoteIP, port, virtClient)
File "virtnbdbackup", line 706, in connectNbd
return nbdClient.connect()
File "/home/playys/backupScript/virtnbdbackup/libvirtnbdbackup/nbdcli/client.py", line 135, in connect
connection = self._connect()
File "/home/playys/backupScript/virtnbdbackup/libvirtnbdbackup/nbdcli/client.py", line 111, in _connect
self._getBlockInfo()
File "/home/playys/backupScript/virtnbdbackup/libvirtnbdbackup/nbdcli/client.py", line 92, in _getBlockInfo
maxSize = self.nbd.get_block_size(nbd.SIZE_MAXIMUM)
AttributeError: 'NBD' object has no attribute 'get_block_size'
[2023-04-02 16:22:54] INFO root virtnbdbackup - main [MainThread]: Backup jobs finished, stopping backup task.
[2023-04-02 16:22:54] INFO root metadata - backupConfig [MainThread]: Saving VM config to: [/mnt/sdb/winServerBackups//vmconfig.virtnbdbackup.0.xml]
[2023-04-02 16:22:54] INFO root metadata - backupDiskInfo [MainThread]: Saved qcow image config to: [/mnt/sdb/winServerBackups//sda.virtnbdbackup.0.qcow.json]
[2023-04-02 16:22:54] INFO root metadata - backupAutoStart [MainThread]: Autostart setting configured for virtual machine.
[2023-04-02 16:22:54] ERROR root virtnbdbackup - main [MainThread]: Error during backup

[abbbi]

please see old issues, your libnbd version installed is either too old or you have installed the nbd module from pypi, which is the wrong one...

[abbbi]

See: #20

your python-libnbd bindings (libnbd version: 1.2.2) are too old

you can try the ones i backported for the CI environment or you have to backport them yourself or use a virtualenv.

The urls for the packages i used have been removed from the code meanwhile because i switched my CI
to ubuntu 22.x, here are the links:

-        # ubuntu 20.x does only include libnbd 1.2.2 which is too old
-        # update package for ci testing to newer version backported.
-        # also copy nbdinfo from debian bullseye, for tests with
-        # option -q
-        wget https://abbbi.github.io/files/libnbd0_1.6.2-1_amd64.deb
-        wget https://abbbi.github.io/files/python3-libnbd_1.6.2-1_amd64.deb