Tested proposed on Lunar

1. Start VM

2. upgrade packages
# apt update -y && sudo apt upgrade -y

3. Enable proposed (multipath-tools installed by default)
# cat <<EOF >/etc/apt/sources.list.d/ubuntu-$(lsb_release -cs)-proposed.list
# Enable Ubuntu proposed archive
deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -cs)-proposed restricted main multiverse universe
EOF

4. Install required packages
# apt install -y lsscsi multipath-tools open-iscsi tgt

5. Update to proposed package
# apt install -y kpartx=0.8.8-1ubuntu2.1
# apt install -y multipath-tools=0.8.8-1ubuntu2.1

6. Confirm package
# apt-cache policy multipath-tools | grep Installed
  Installed: 0.8.8-1ubuntu2.1

7. Setup local test targets
cp file to setup.sh
```
targetname="iqn.2016-11.foo.com:target.iscsi"
cwd=$(pwd)
testdir="/mnt/tgtmpathtest"
localhost="127.0.0.1"
portal="${localhost}:3260"
maxpaths=4
backfn="backingfile"
expectwwid="60000000000000000e00000000010001"
testdisk="/dev/disk/by-id/wwn-0x${expectwwid}"

### Setup mpath devices

# Restart tgtd to make sure modules are all loaded
service tgt restart || echo "Failed to restart tgt" >&2

# prep SINGLE test file
truncate --size 100M ${backfn}

# create target
tgtadm --lld iscsi --op new --mode target --tid 1 -T "${targetname}"
# allow all to bind the target
tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL
# set backing file
tgtadm --lld iscsi --op new --mode logicalunit --tid 1 --lun 1 -b "${cwd}/${backfn}"

# scan for targets (locally)
iscsiadm --mode discovery --type sendtargets --portal ${localhost}

# login
echo "login #1"
iscsiadm --mode node --targetname "${targetname}" --portal ${portal} --login
# duplicate this session (always 1)
for i in $(seq 2 ${maxpaths})
do
    echo "extra login #${i}"
    iscsiadm --mode session -r 1 --op new
done

udevadm settle
sleep 5 # sleep a bit to allow device to be created.

# status summary
echo "Status after initial setup"
tgtadm --lld iscsi --mode target --op show
tgtadm --lld iscsi --op show --mode conn --tid 1
iscsiadm --mode session -P 1
lsscsi -liv
multipath -v3 -ll
dmsetup table

echo "Test WWN should now point to DM"
readlink "${testdisk}" | grep dm
```
# chmod +x setup.sh
# ./setup.sh

8. Test Behavior from proposed
# mpathpersist -v2 --out --register-ignore --param-sark=0x214872831999999 /dev/dm-0
75.192551 | mpatha: adding new path sda
75.194082 | mpatha: adding new path sdc
75.195587 | mpatha: adding new path sdb
75.197020 | mpatha: adding new path sdd
75.197708 | mpatha: pr message=setprstatus map mpatha
75.197859 | mpatha: message=setprstatus map mpatha reply=ok

Looks good.

9. Test failing behavior
# apt install -y kpartx=0.8.8-1ubuntu2 --allow-downgrades
# apt install -y multipath-tools=0.8.8-1ubuntu2 --allow-downgrades
# mpathpersist -v2 --out --register-ignore --param-sark=0x214872831999999 /dev/dm-0
131.542153 | mpatha: adding new path sda
131.544790 | mpatha: adding new path sdc
131.546989 | mpatha: adding new path sdb
131.550224 | mpatha: adding new path sdd
131.551471 | mpatha: pr message=map mpatha setprstatus
131.553267 | mpatha: message=map mpatha setprstatus reply=map mpatha setprstatus: Missing argument
multipath-tools v0.8.8 (03/12, 2021)
CLI commands reference:
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