Re: find libxml2 using pkg-config

On Wed, Mar 20, 2013 at 05:17:11PM -0400, Peter Eisentraut wrote:
> On 3/4/13 1:36 PM, Noah Misch wrote:
> > Do you have in mind a target system exhibiting a problem? CentOS 6 ships a
> > single xml2-config, but its --cflags --libs output is the same regardless of
> > the installed combination of libxml2-dev packages. Ubuntu 13.04 does not ship
> > 32-bit libxml2, so it avoids the question.
>
> It does, because you can just install the libxml2 package from the
> 32-bit distribution. (So there will no longer be packages in the 64-bit
> distribution that actually contain 32-bit code, at least in the long run.)

Ah, interesting. Is there a plan or existing provision for arbitrating the
resulting /usr/bin contents when mixing packages that way?

> But pack to the main question: Stock systems probably won't exhibit the
> problem, because they just dodge the problem by omitting the -L option
> from the xml2-config output and rely on the default linker paths to do
> the right thing. But if you use a nondefault libxml2 install or a
> nondefault compiler, interesting things might start to happen.
>
> I think at this point, the issue is probably too obscure, and the people
> affected by it hopefully know what they are doing, so it might not be
> important in practice. In light of the other flaws that you have
> pointed out, I'd be fine with withdrawing this patch for now. But we
> should keep an eye on the situation.

Agreed. Convincing a package to properly attach to its dependencies is no
fun. I wanted to like this patch.

--
Noah Misch
EnterpriseDB http://www.enterprisedb.com