The RPM spec files should Obsolete the old package names of version 4 of the ZFS libraries

[siebenmann]

System information

Type	Version/Name
Distribution Name	Fedora
Distribution Version	33
Linux Kernel	5.11.10-200.fc33.x86_64
Architecture	x86_64
ZFS Version	git tip, currently zfs-2.1.0-rc1-20-gec580225d
SPL Version	git tip, currently zfs-2.1.0-rc1-20-gec580225d

Describe the problem you're observing

Commit fe6babc changes the RPM spec files so that they now produce libzfs5 and libzpool5 RPMs (and shared library versions), instead of libzfs4 and libzpool4 RPMs. However, the RPM spec files don't Obsoletes the old versions, leading to upgrade time conflicts. This is a rerun of issue #11230 from the previous library version bump.

This time around there appear to be no conflicts between libzpool5 and libzpool4, but it's probably a good thing to Obsolete that one too. Also, the fact that there are conflicts between libzfs5 and libzfs4 may be a sign that some shared libraries have not had their versions increased when they should have.

Describe how to reproduce the problem

Install a Fedora system with RPMs built from ZFS git tip before this commit, pull, rebuild the RPMs, and attempt to update with `dnf update *.rpm'. For me, this produces:

# dnf update *.rpm
Upgrading:
 libnvpair3        x86_64        2.1.99-1.fc33        @commandline         40 k
 libuutil3         x86_64        2.1.99-1.fc33        @commandline         32 k
 zfs               x86_64        2.1.99-1.fc33        @commandline        660 k
 zfs-dkms          noarch        2.1.99-1.fc33        @commandline         29 M
Installing dependencies:
 libzfs5           x86_64        2.1.99-1.fc33        @commandline        237 k
 libzpool5         x86_64        2.1.99-1.fc33        @commandline        1.3 M

Transaction Summary
================================================================================
Install  2 Packages
Upgrade  4 Packages

Total size: 32 M
Is this ok [y/N]: y
Downloading Packages:
Running transaction check
Transaction check succeeded.
Running transaction test
Error: Transaction test error:
  file /lib64/libzfs.so.4 from install of libzfs5-2.1.99-1.fc33.x86_64 conflicts with file from package libzfs4-2.0.0-rc1_471_g38280c352.fc33.x86_64
  file /lib64/libzfs_core.so.3.0.0 from install of libzfs5-2.1.99-1.fc33.x86_64 conflicts with file from package libzfs4-2.0.0-rc1_471_g38280c352.fc33.x86_64
  file /lib64/libzfsbootenv.so.1.0.0 from install of libzfs5-2.1.99-1.fc33.x86_64 conflicts with file from package libzfs4-2.0.0-rc1_471_g38280c352.fc33.x86_64

[behlendorf]

@siebenmann thanks for catching this again. I've opened #11847 to obsolete the old packages.

there are conflicts between libzfs5 and libzfs4 may be a sign that some shared libraries have not had their versions increased when they should have.

The conflicting libraries didn't need a version bump in this case since they were unchanged. However, I do think this points out a possible issue in the packaging since the libzfs5 package includes more than just that one library.

[siebenmann]

Unfortunately it looks like at least one RPM was missed, libzfs5-devel, which needs to obsolete libzfs4-devel (I didn't notice this immediately because I don't have the -devel package installed on all of my machines).

[behlendorf]

Thanks I'll open a PR for it. Sorry I'm not sure how I overlooked that
.

[siebenmann]

I think it's just hard to remember. Perhaps a comment block in the zfs.spec.in is called for, with a 'do this if you're increasing the .so version'. There will be future times and people's memories for infrequent procedures are always imperfect.

(And I missed the -devel package myself when I was looking at the zfs.spec.in for the first bug report.)

[behlendorf]

Good idea, I've opened #11895 which adds the missing obsoletes and a comment.