Re: 9.5 make world failing due to sgml tools missing

>> libxml2 has been a required documentation build tool since PostgreSQL
>> 9.0. The only thing that's new is that xmllint is in a different
>> subpackage on some systems. So just install that and you're all set for
>> the foreseeable future.
>>
> Well, something is different in 9.5. On this same system (Linux Mint 17.1)
> I can build all previous versions with "make world" and I do not get this
> error.

Maybe the error on the missing tool was previously ignored (that is it
failed without saying so), and it is now reported?

It might be related to:

commit 5d93ce2d0c619ba1b408eb749715e7223e23f6ae
Author: Peter Eisentraut <peter_e(at)gmx(dot)net>
Date: Tue Oct 21 14:46:38 2014 -0400

doc: Check DocBook XML validity during the build

Building the documentation with XSLT does not check the DTD, like a
DSSSL build would. One can often get away with having invalid XML, but
the stylesheets might then create incorrect output, as they are not
designed to handle that. Therefore, check the validity of the XML
against the DTD, using xmllint, during the build.

Add xmllint detection to configure, and add some documentation.

xmllint comes with libxml2, which is already in use, but it might be
in a separate package, such as libxml2-utils on Debian.

Reviewed-by: Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>

--
Fabien.