libxcb-xlib.la failures when building X11 with libxcb-1.2

[Bill Crawford]

On Wednesday 18 March 2009 15:50:08 Simon Thum wrote:
> Dan Nicholson wrote:
> > Debian (and Ubuntu by proxy) has a patch that makes libtool only add
> > needed libraries (i.e., those added on the command line) to the
> > dependency_libs setting in .la files. Unfortunately, I think it still
> > has a few corner case bugs that make it not upstream acceptable. I
> > think this is it:
> >
> > http://patches.ubuntu.com/libt/libtool/extracted/link_all_deplibs.patch
>
> I must say I don't know too much about dynamic linking and ELF, but I
> know enough about how it should be to be appalled when I first realized
> what got into those .la's. It eludes me why this deps-of-deps-of... went
> into libtool in the first place.
>
> Care to explain to a noob?

Some operating systems (notably AIX at one point, not sure if it's still the 
case) need for their binaries to be linked against *all* libraries that will be 
loaded at runtime. Also, static linking may require all the dependencies to be 
included on the command line at link time. Libtool sort of abstracts this, but 
to do so it needs to keep track of what those dependencies are, and does so by 
storing them in this .la file.

In theory, rebuilding libX11 without this dependency, then rebuilding everything 
that uses it, and so on, should clear these deps out of the .la files, but it's 
a bit of a pain that they're there at all, and that this impacts all the users 
of libX11 both direct and indirect.