Failing to install wichita (P8) - sgdisk fails to create the partition on /dev/md0

ipmi is working, I have tracked the install and it seems "normal" until it breaks reproducible 5/5 tries now.

Here the install log from maas UI, lets look in there

FYI: maas is on 2.3.3 (6498-ge4db91d-0ubuntu1~16.04.1)

Hmm, look at this:
        Running command ['blkid', '-o', 'export', '/dev/sdh1'] with allowed return codes [0, 2] (capture=True)
        Writing dname udev rule '['SUBSYSTEM=="block"', 'ACTION=="add|change"', 'ENV{DEVTYPE}=="partition"', 'ENV{ID_PART_ENTRY_UUID}=="5d3e4029-081f-4dd3-b978-23714623e5a5"', 'SYMLINK+="disk/by-dname/sdh-part1"\n']'
        finish: cmd-install/stage-partitioning/builtin/cmd-block-meta: SUCCESS: configuring partition: sdh-part1
        start: cmd-install/stage-partitioning/builtin/cmd-block-meta: configuring partition: md0-part1
        get_path_to_storage_volume for volume md0
        devsync for /dev/md0
        Running command ['partprobe', '/dev/md0'] with allowed return codes [0, 1] (capture=False)
        Running command ['udevadm', 'settle'] with allowed return codes [0] (capture=False)
        devsync happy - path /dev/md0 now exists
        return volume path /dev/md0
        md0 logical_block_size_bytes: 512
        adding partition 'md0-part1' to disk 'md0' (ptable: 'gpt')
        partnum: 1 offset_sectors: 2048 length_sectors: 2231418879
        Preparing partition location on disk /dev/md0
        Wiping 1M on /dev/md0 at offset 1048576
        Running command ['sgdisk', '--new', '1:2048:2231420927', '--typecode=1:8300', '/dev/md0'] with allowed return codes [0] (capture=True)
        An error occured handling 'md0-part1': ProcessExecutionError - Unexpected error while running command.
        Command: ['sgdisk', '--new', '1:2048:2231420927', '--typecode=1:8300', '/dev/md0']
        Exit code: 4
        Reason: -
        Stdout: Creating new GPT entries.

        Stderr: Could not create partition 1 from 2048 to 2231420927
                Could not change partition 1's type code to 8300!
                Error encountered; not saving changes.

        finish: cmd-install/stage-partitioning/builtin/cmd-block-meta: FAIL: configuring partition: md0-part1
        finish: cmd-install/stage-partitioning/builtin/cmd-block-meta: FAIL: curtin command block-meta
        Traceback (most recent call last):
          File "/curtin/curtin/commands/main.py", line 201, in main
            ret = args.func(args)
          File "/curtin/curtin/commands/block_meta.py", line 58, in block_meta
            meta_custom(args)
          File "/curtin/curtin/commands/block_meta.py", line 1484, in meta_custom
            handler(command, storage_config_dict)
          File "/curtin/curtin/commands/block_meta.py", line 601, in partition_handler
            util.subp(cmd, capture=True)
          File "/curtin/curtin/util.py", line 266, in subp
            return _subp(*args, **kwargs)
          File "/curtin/curtin/util.py", line 132, in _subp
            cmd=args)
        curtin.util.ProcessExecutionError: Unexpected error while running command.
        Command: ['sgdisk', '--new', '1:2048:2231420927', '--typecode=1:8300', '/dev/md0']
        Exit code: 4
        Reason: -
        Stdout: Creating new GPT entries.

        Stderr: Could not create partition 1 from 2048 to 2231420927
                Could not change partition 1's type cod...

type is "8300 Linux filesystem"
Retval 4 is "4 An error prevented saving changes"
The size is ~1TB which sounds reasonable.

I found that the log actually contains two failed sgdisk calls.
Earlier there also is:

Wiping 1M on /dev/md0 at offset 1048576W
Running command ['sgdisk', '--new', '1:2048:2231420927', '--typecode=1:8300', '/dev/md0'] with allowed return codes [0] (capture=True)R
An error occured handling 'md0-part1': ProcessExecutionError - Unexpected error while running command.A
Command: ['sgdisk', '--new', '1:2048:2231420927', '--typecode=1:8300', '/dev/md0']C
Exit code: 4E
Reason: -R
Stdout: Creating new GPT entries.S

Stderr: Could not create partition 1 from 2048 to 2231420927S
        Could not change partition 1's type code to 8300!
        Error encountered; not saving changes.

Seems pretty much the same to me.

Config in maas says:
md0-part1 1.1 TB ext4 /srv
sda-part2 1.1 TB ext4 /

I'd not need that md0, so lets kill it...

Ok, that was it.
So we have two POVs here:

1. somebody has set up a /dev/md0 based config to screw others up deploying the system (bad luck for me and bad people not removing bad config after tests)

2. maas/curtin should be able to handle the config and get this installed
   But since I didn't create the md0 config I can't prove that it was valid.
   I'll set it to incomplete, if you can ready more from the logs and find a bug - yeah.
   Otherwise please mark it invalid.

The remaining bug in this is a dup, closing as that.