gistfile1.txt

deleteme ~ # cat /tmp/growpart2.uwhOpe/new.out
label: dos
label-id: 0xe4a8d41d
device: /dev/vda
unit: sectors
sector-size: 512

/dev/vda1 : start=        2048, size=     41940959, type=83, bootable
deleteme ~ # cat /tmp/growpart2.uwhOpe/new.out | sfdisk /dev/vda --force --no-reread
Disk /dev/vda: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe4a8d41d

Old situation:

Device     Boot Start     End Sectors Size Id Type
/dev/vda1  *     2048 6289407 6287360   3G 83 Linux

>>> Script header accepted.
>>> Script header accepted.
>>> Script header accepted.
>>> Script header accepted.
>>> line 5: unsupported command

New situation:
Disklabel type: dos
Disk identifier: 0xe4a8d41d

Device     Boot Start     End Sectors Size Id Type
/dev/vda1  *     2048 6289407 6287360   3G 83 Linux
Leaving.