RPM macros question

[Paul Howarth]

On Thu, 02 Aug 2012 13:21:54 -0600
Dmitry Makovey <dmitry at athabascau.ca> wrote:

> On August 2, 2012 20:12:10 Paul Howarth wrote:
> > I don't think there's a standard for this, but an approach I've used
> > with success is to test for the existence of the /run/lock
> > directory:
> > 
> > # If directory /run/lock exists, do a systemd-based build;
> > otherwise,a sysvinit-based build 
> > %global use_systemd %([ -d /run/lock ] && echo 1 || echo 0)
> 
> That's a good idea, thanks Paul.
> 
> Being paranoid I'm thinking of adding a step:
> 
> %global use_systemd %([ -d /run/lock ] && rpm --quiet -qf /run/lock
> && echo 1 || echo 0)
> 
> that should make sure /run/lock is not there because it happened that
> sysadmin just decided create it manually and doesn't happen to run
> any systemd... Does that make sense?

Well it's fine in principle but unfortunately accessing the rpm
database like that from within a package build is a bad idea because
the build system may be using a chroot populated by a different version
of rpm than the one the target system uses, which could make the rpm
database unreadable at package build time, for instance if the builder
and target systems use different versions of Berkeley DB.

The mock approach used in Fedora/EPEL is affected by this.

Paul.