This was fixed in commit 9e196cc2902255c32. What triggered it was the fact that you ran parted /dev/sda1 when you meant /dev/sda.
anarchonerd writes: > Hello, > > I hope I am contacting the right adress here or that it, in case I > didn't, can get forwarded. I just got an error > message from parted that said I found a bug. As I don't know how exactly > to check whether it was fixed or > not I thought I'll just report it anyway as a bugreport too much is > likely better than one too little. > > I was installing arch linux on a non-efi system and tried to toggle a > bootable flag on my boot partition. That failed. > Attached pictures of what happened. > > Feel free to contact me in case you need more details, I'd provide them > as good as I can. Have a nice day! > > > - anarchonerd
