Emacs 26.1: ./configure does not find my GTK

[a . daniel . eliason]

I'm trying to compile from the current 26.1 tarball on CentOS..  It stops 
because it can't find by GTK. Anybody have similar problem?

My GTK libs are in to /usr/lib64:

  -bash-4.2$ ls /usr/lib64/libgtk*
  /usr/lib64/libgtk-3.so.0  /usr/lib64/libgtk-3.so.0.2200.26  
/usr/lib64/libgtk-x11-2.0.so.0  /usr/lib64/libgtk-x11-2.0.so.0.2400.31

There is no GTK in my 32 bit libs, however:

  -bash-4.2$ ls /usr/lib/libgtk*
  ls: cannot access /usr/lib/libgtk*: No such file or directory
  -bash-4.2$ 

When I run./configure, it does not find the 64 bit libs, apparently:

  <...clipped>
  checking for GTK... no
  checking for GTK... no
  checking for DBUS... yes
  checking for dbus_watch_get_unix_fd... yes
  checking for dbus_type_is_valid... yes
  checking for dbus_validate_bus_name... yes
  checking for dbus_validate_path... yes
  checking for dbus_validate_interface... yes
  checking for dbus_validate_member... yes
  checking for GSETTINGS... yes
  checking whether GSettings is in gio... yes
  checking for GOBJECT... yes
  checking for lgetfilecon in -lselinux... yes
  checking for LIBGNUTLS... no
  checking for LIBSYSTEMD... no
  checking sys/inotify.h usability... yes
  checking sys/inotify.h presence... yes
  checking for sys/inotify.h... yes
  checking for inotify_init1... yes
  checking for xaw3d... no
  checking for libXaw... configure: error: No X toolkit could be found.
  If you are sure you want Emacs compiled without an X toolkit, pass
    --with-x-toolkit=no
  to configure.  Otherwise, install the development libraries for the toolkit
  that you want to use (e.g. Gtk+) and re-run configure.
  -bash-4.2$

I did try "yum install gtk+", and it did a bunch of work, but it made no 
difference.  I even tried installing "xaw" from yum, 'cause I saw ./configure 
was looking for it, but that made no difference either.

I tried setting LD_LIBRARY_PATH, but it did not help

  -bash-4.2$ echo $LD_LIBRARY_PATH
  /usr/lib64:/usr/lib:/usr/local/lib64:/usr/local/lib
  -bash-4.2$

My /etc/ld.so.conf is

  -bash-4.2$ cat /etc/ld.so.conf
  include ld.so.conf.d/*.conf
  /usr/lib64
  /usr/lib
  -bash-4.2$ cat /etc/ld.so.conf.d/*.conf
  /usr/local/lib
  /usr/local/lib64
  /usr/local/lib
  /usr/local/lib64
  /usr/local/lib
  /usr/local/lib64
  /usr/lib64/mysql
  /usr/pgsql-9.4/lib
  -bash-4.2$

It seems like emacs ./configure really doesn't know how to deal with the 64 bit 
libraries??