[systemd-devel] systemd build dependency on dbus

[Lennart Poettering]

On Thu, 23.10.14 12:44, Simon McVittie (simon.mcvittie at collabora.co.uk) wrote:

> On 23/10/14 12:21, Lennart Poettering wrote:
> > The behaviour should really be to:
> > 
> > 1. take the paths from configure switches
> > 2. if they are not specified, try to get them from pkg-config
> > 3. if the relevant pkg-config files are not installed, generate an error and refuse build
> 
> Actually... with D-Bus maintainer hat on, I think it's better for
> non-dbus packages to use their own ${sysconfdir}/dbus-1/system.d,
> ${datadir}/dbus-1/services and so on, rather than querying dbus'
> pkg-config file (analogous to the behaviour prescribed for XDG_DATA_DIRS
> in the XDG basedir specification). That's what I recommended in the
> D-Bus Specification.
> 
> I consider the dbus-1/services and dbus-1/system-services paths to be
> part of D-Bus, and they are specifically described in the D-Bus
> Specification. The status of ${sysconfdir}/dbus-1/system.d is a bit less
> clear-cut, but if we ever changed it, we'd break every system service.
> 
> In particular, even if dbus-daemon is installed in /opt or something, it
> is hard-coded to look for services in /usr/local and /usr as well as its
> own ${prefix} (and the Specification says so). If someone is installing
> software in a non-/usr tree, they're doing that because they want to
> isolate it for whatever reason, and we probably shouldn't second-guess
> that; if they want to search /opt/gnome (or whatever) in addition, it's
> easy to configure dbus-daemon to do that, by dropping a file into system.d.
> 
> This seems doubly true for systemd, which is the sort of thing that
> really ought to be installed to (/etc and) /usr by the distribution
> vendor in any case, so the system dbus-daemon is always going to pick it up.
> 
> dbus-1.pc is mainly the pkg-config metadata for libdbus, the reference C
> implementation of D-Bus. The abstract D-Bus protocol that has been
> reimplemented by packages like dbus-sharp, dbus-java, GLib (GDBus) and
> systemd (sd-bus) should not require use of libdbus, and libdbus isn't
> even the implementation I recommend to most C authors (that would be
> GLib's).

Makes sense I guess. Except for the bits in /etc that really should be
in /usr anyway...

I'd take a patch that removes the pkg-config hook-up for dbus entirely
from configure.ac then.

Lennart

-- 
Lennart Poettering, Red Hat