From curtin's install.log:
Running command ['blockdev', '--rereadpt', '/dev/vda'] with allowed return codes [0] (capture=True) Error rescanning devices, possibly known issue LP: #1489521 cmd: ['blockdev', '--rereadpt', '/dev/vda'] stdout:'' stderr:blockdev: ioctl error on BLKRRPART: Device or resource busy exit_code:1
From curtin's install.log:
Running command ['blockdev', '--rereadpt', '/dev/vda'] with allowed return codes [0] (capture=True)
Error rescanning devices, possibly known issue LP: #1489521
cmd: ['blockdev', '--rereadpt', '/dev/vda']
stdout:''
stderr:blockdev: ioctl error on BLKRRPART: Device or resource busy
exit_code:1