So many issues on clean, fresh Ubuntu 21.04 install

[zilexa]

1. installing from ubuntu repository installs version. With this version 0.8.15, no /etc/sysconfig/snapper folder is created, snapper can create configs, they work. There is no dependency on that sysconfig folder. All works fine.
2. Adding the snapper repository as explained on the website and updating snapper leads to errors (sudo apt upgrade) , snapper installation fails because /etc/snapper/config contains files.
3. After renaming that folder to configbackup and running:

sudo apt --fix-broken install
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  ethtool libbtrfs0 libsnapper5 pibootctl
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
  libsnapper
The following NEW packages will be installed:
  libsnapper
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
14 not fully installed or removed.
Need to get 0 B/252 kB of archives.
After this operation, 902 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
(Reading database ... 271331 files and directories currently installed.)
Preparing to unpack .../libsnapper_0.9.0-1_amd64.deb ...
Unpacking libsnapper (0.9.0-1) ...
dpkg: error processing archive /var/cache/apt/archives/libsnapper_0.9.0-1_amd64.deb (--unpack):
 trying to overwrite '/etc/snapper/config-templates/default', which is also in package snapper 0.9.0-1
dpkg-deb: error: paste subprocess was killed by signal (Broken pipe)
Errors were encountered while processing:
 /var/cache/apt/archives/libsnapper_0.9.0-1_amd64.deb
snapper: symbol lookup error: snapper: undefined symbol: _ZNK7snapper4UuidltERKS0_
snapper: symbol lookup error: snapper: undefined symbol: _ZNK7snapper4UuidltERKS0_
E: Sub-process /usr/bin/dpkg returned an error code (1)

4. To solve this, sudo apt purge snapper was not enough, I needed to do sudo apt remove libsnapper5 as well.

5. Now, installing snapper (from its own repository) works. But now the /etc/sysconfig/snapper file is created! (note it didn't exist in step 1 with version 0.8.15). But my god the inconsistency! Even if I copy my (backupped and previously working!) config files to /etc/snapper/config, snapper ls complains no root config exists (even after adding them properly to /etc/sysconfig/snapper!!), but snapper -c root create-config complains it already exist.

$ sudo snapper -c root create-config /
Creating config failed (config already exists).
$ sudo snapper ls
The config 'root' does not exist. Likely snapper is not configured.
See 'man snapper' for further instructions.

This output combination should not be possible.

I cannot imagine why Snapper is so inconsistent.

6. Now I removed (purged) snapper again, removed /etc/sysconfig and /etc/snapper, removed libsnapper. Removed snapper repository and then installed snapper again. I am back on version 0.8.15. I can create the root config, no /etc/sysconfig/snapper file exists.
7. However, when I manually delete /etc/snapper/configs/root and run the create-config command again, snapper complains the file already exist! How is that possible? Does snapper have an additional location for config files? EDIT: found it: /etc/default/snapper

Much of this, or all of this, is no where documented. Why does snapper require someone to do this much trial and error to figure out how to set it up?

[henrich]

With this version 0.8.15, no /etc/sysconfig/snapper folder is created

(With Debian package maintainer hat) Yes, Debian/Ubuntu system does not have any settings with /etc/sysconfig, so I treat it as so. Upstream provides the different deb packages from Debian/Ubuntu.