Re: [PATCH] tools/configure: Check if pixman is present on the system

[Ian Campbell <Ian.Campbell@citrix.com>]

On Wed, 2015-01-14 at 10:43 +0000, Wei Liu wrote:
> On Wed, Jan 14, 2015 at 10:39:45AM +0000, Ian Campbell wrote:
> > On Wed, 2015-01-14 at 07:11 +0000, Jan Beulich wrote:
> > > >>> Julien Grall <julien.grall@linaro.org> 01/13/15 7:17 PM >>>
> > > >QEMU upstream requires the use of pixman. When pixman is not present the
> > > >system, the configure of QEMU will fail with:
> > > >
> > > >ERROR: pixman not present. Your options:
> > > >(1) Preferred: Install the pixman devel package (any recent
> > > >distro should have packages as Xorg needs pixman too).
> > > >(2) Fetch the pixman submodule, using:
> > > >git submodule update --init pixman
> > > >
> > > >I think we can use by default the version on the system. So check it
> > > >a Xen configuration time to avoid a build issue later.
> > > 
> > > Since qemu building isn't a required part of building the tools, is a check in
> > > the tools configure process really an appropriate thing to do?
> > 
> > It's quite annoying as a user to have configure appear to succeed and
> > then the build to fail due to a missing dependency (whether in a 3rd
> > party component or not).
> > 
> > We could make this check conditional on --with-qemu-system not being
> > given, but given the library is readily available I don't think its the
> > end of the world to have a potentially unnecessary check.
> > 
> > A far more heavy weight (but probably better) solution would be to
> > arrange for the clone (and necessary downloads) + submodule configure to
> > happen at configure rather than build time. That's a much bigger job
> > though and I wouldn't expect anyone to take that on unless they are
> > super duper keen.
> > 
> 
> Or we can state clearly in README / INSTALL that Xen's configure doesn't
> check for external projects' dependencies so that we don't end up adding
> check for every new dependency in QEMU. Just my 2 cents.

Having it written down doesn't make it any less annoying when you trip
over it though ;-)

(I'm fine if this is the consensus though)

Ian.