[systemd-devel] Minimal builds

[Bryan Kadzban]

Bryan Kadzban wrote:
> On Wed, Jun 20, 2012 at 06:22:49PM +0200, Lennart Poettering wrote:
>> Heya,
>>
>> regarding the whole discussion on minimal builds and people wanting to
>> pick specific parts of the systemd build leaving out others, beyond what
>> the configure switches offer: Here are some guidelines how we recommend
>> people to do this:
>>
>> http://freedesktop.org/wiki/Software/systemd/MinimalBuilds
>>
>> From our side this should be enough to settle the discussion.
> 
> Would an extremely minimal patch (just to configure.ac, not touching any
> of the pkg-config dependencies, but only intltool, libcap, and gperf),
> allowing them to be made optional, be acceptable to systemd?

Note that the patch would not need to create a new configure switch,
either; it could just as easily trigger off some environment variable,
if there's a worry that its presence in the "./configure --help" output
could cause people to use it without understanding what it does, and
break their systemd build.

(Same as DBUS_CFLAGS / DBUS_LIBS overriding pkg-config today, actually.
Something like SYSTEMD_ONLY_DEPS_OPTIONAL, or whatever; the name isn't
exactly critical I don't think.)

I have sent a patch adding a libcap.pc file to the libcap installation,
to morgan@ -- not sure what will happen there, but that will help a bit
if it gets in.

But thinking more along those lines, I should consider changing
intltool's m4 script to allow it to be found via pkg-config, as well,
and changing gperf to install a .pc file like the patch to libcap.  Then
nothing would need to be changed in systemd at all, except using
PKG_CHECK_EXISTS for these deps instead of AC_CHECK_TOOL and an
AC_MSG_ERROR.  (And nothing should be required for intltool; the
existing IT_PROG_INTLTOOL should keep working.)