bug#19425: "You found a bug on GNU Parted!"

Running version 3.2 on Parabola GNU/Linux-libre. Was going to turn on the boot flag of an otherwise prepped FAT32 flash drive.

"The bug has most likely not affected any of your data."

Error message: parted DEVICE unit co print unit s print

Command history:
p
m
disk_set
n
n
h disk_set
h pmbr_boot
boot
on

-- And that's when it happened.

There's also another bit at the bottom of the message after "include any additional information"...

Unknown disk flag, 0.
Error: The flag '(null)' is not available for loop disk labels.

Cheers