apt upgrade で ping(inetutils-ping) が壊れていると言われて失敗する

Debian sid amd64 環境で,apt upgrade するとこんなエラーで失敗しました.

$ sudo apt upgrade
Reading package lists... Done
Building dependency tree     
Reading state information... Done    
Calculating upgrade... Done          
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.         
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 inetutils-ping : Conflicts: ping
E: Broken packages 

ping コマンドはあるし実行も出来る.reinstall してみましたがエラーは解消されず.

$ sudo apt install --reinstall inetutils-ping                                                                     
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following package was automatically installed and is no longer required:
  python-newt
Use 'sudo apt autoremove' to remove it.
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 57 not upgraded.
Need to get 0 B/226 kB of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 472864 files and directories currently installed.)
Preparing to unpack .../inetutils-ping_2%3a1.9.4-7_amd64.deb ...
Unpacking inetutils-ping (2:1.9.4-7) over (2:1.9.4-7) ...
Setting up inetutils-ping (2:1.9.4-7) ...
Processing triggers for man-db (2.8.5-2) ...

一時的に削除してみました.

$ sudo apt remove inetutils-ping
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  python-newt
Use 'sudo apt autoremove' to remove it.
The following packages will be REMOVED:
  inetutils-ping
0 upgraded, 0 newly installed, 1 to remove and 57 not upgraded.
After this operation, 358 kB disk space will be freed.
Do you want to continue? [Y/n] 
(Reading database ... 472864 files and directories currently installed.)
Removing inetutils-ping (2:1.9.4-7) ...
Processing triggers for man-db (2.8.5-2) ...

削除した後 apt upgrade を試すと通りました.

$ sudo apt upgrade

その後 ping を install し直したあと upgrade を試すとエラーは出なくなりました.

$ sudo apt install inetutils-ping
$ sudo apt upgrade>/dev/null 2>&1;echo $?
0

原因がよくわからないですね…….

環境

$ dpkg-query -W apt inetutils-ping
apt     1.8.0
inetutils-ping  2:1.9.4-7
$ lsb_release -dr
Description:    Debian GNU/Linux 10 (buster)
Release:        10
$ uname -m
x86_64