I don't like get_lastlog2() and original get_lastlog(). It would be nice to cache the lastlog entry in the struct lslogins_user to avoid many seek & reads (and SQL requests in lastlog2). But it's unrelated to this pull request, and it is better to address it with another PR.

Any chance for a testcase? :-)

Yes, you are right :-) I have added one.

Hm, there are some issues in the build environments. E.G. fedora:
nothing provides liblastlog2.so.2(LIBLASTLOG2_2_40)(64bit) needed by util-linux-2.40.rc1-4.20240125171921182063.pr2735.4.gbf7f26be8.fc40.x86_64
And it seems that some debian builds do not have "sqlite3".

For debian have a look at .github/workflows/cibuild-setup-ubuntu.sh
For Fedora I don't know.

For Fedora maybe .packit.yaml needs to be adapted so it modifies util-linux.spec to specify that liblastlog2 is provided by util-linux itself.
But that is mostly a guess.

I do not get it:

nothing provides liblastlog2.so.2()(64bit) needed by util-linux-2.40.rc1-4.20240125171921182063.pr2735.4.gbf7f26be8.fc40.x86_64

I cannot find any requirement in the *.spec file under:

https://copr-dist-git.fedorainfracloud.org/git/packit/util-linux-util-linux-2735/util-linux in the given branch.

Where is this requirement still defined ?

I think the requirement is extracted from the actual lsogins binary that is being built.
And the spec file does not define a package that contains the liblastlog2.

The spec file is from the official Fedora rawhide, and it needs to be updated for v2.40-rc1. I'll update it ...

BTW, we need to do something with login-utils/login.c. Now, it directly reads/writes to the classic last log file. This code should be optional (and enabled/disabled) independently on lastlog2 as you can replace it with old pam_lastlog or new pam_lastlog2.

I suggest introducing #ifdef USE_LOGIN_LASTLOG and --enable-login-lastlog and making it disabled by default for the next release with some highlight warnings in ReleaseNotes.

I suggest introducing #ifdef USE_LOGIN_LASTLOG and --enable-login-lastlog and making it disabled by default for the next release with some highlight warnings in ReleaseNotes.

Ok, good point. Will do it...

I suggest introducing #ifdef USE_LOGIN_LASTLOG and --enable-login-lastlog and making it disabled by default for the next release with some highlight warnings in ReleaseNotes.

Ok, good point. Will do it...

Have done it :-)

The rpm-build:fedora-rawhide-* test does not pass because nothing on Fedora provides liblastlog2.so. I need to change it on Fedora. It is better than fixing it with some workaround in .packit.yaml.