Re: readutmp: load libsystemd with dlopen instead of linking

On 2026-07-20 13:10, Luca Boccassi wrote:
> If it's required, why can it be disabled with a switch?

The --enable-systemd switch was put in, as I recall, because we figured 
there'd be two kinds of distros: those with systemd where you really 
need systemd for 'who' etc. to work or where you'd prefer systemd to the 
non-systemd approach; and everybody else. We figured distros would 
decided on their own which way to go. Although many distros now use 
systemd, some do not.

Unfortunately some distros mishandle this. For example, my Ubuntu 26.04 
LTS workstation uses systemd but apparently did not build GNU coreutils 
with libsystemd, so its 'who' does not work. However, some distros do 
get it right, e.g., Fedora 44.


> Will you
> accept a patch that drops the --enable-systemd option and makes the
> library always mandatory on Linux?

It doesn't sound right to require --enable-systemd for Linux-based 
platforms that don't use systemd by default for 'who' data. This 
includes platforms like Alpine and Gentoo, along with older Debian etc. 
Even if libsystemd is available, it's not always right for 'who' to use 
libsystemd to get utmp info. This is why we left this up to the distro.