On 11/30/2017 09:43 AM, Elad Lahav wrote:
> The following patch fixes the problem

Thanks, I installed the attached slightly-more-conservative patch into 
the emacs-26 branch.

Hmm, there appears to have been a typo in configure.ac, which I also 
fixed with the attached patch. Why didn't this typo prevent your build 
from working?

> The LIBXML2_CFLAGS variable is bogus, as no special flags are required.
> However, unless this variable being is set to a non-empty string the
> configure script tries to use pkg-config for libxml2, which doesn't
> work.

In what sense doesn't it work? Can we work around this problem 
automatically? After all, if we were willing to live with undocumented 
manual settings, we could have left 'configure' alone and expected 
installers to figure out a command like this one:

./configure --without-makeinfo --with-gnutls=no --with-x-toolkit=no \
   CC=qcc \
   CFLAGS='-D__NO_EXT_QNX' \
   LDFLAGS='-N2MB' \
   LIBXML2_CFLAGS=-I/usr/include \
   LIBXML2_LIBS='-lxml2 -lm'