pkg/53688: emacs25 linking fails with undefined reference to epoxy_has_glx

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         53688
>Category:       pkg
>Synopsis:       emacs25 build fails with undefined reference to epoxy_has_glx
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Oct 27 12:15:00 +0000 2018
>Originator:     Andreas Gustafsson
>Release:        NetBSD 8.0 or -current
>Organization:
>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

When I try to build the editors/emacs25 packge on either NetBSD 8.0
or -current, it fails with the error message

  /usr/pkgsrc/editors/emacs25/work/.buildlink/lib/libgdk-3.so: undefined reference to `epoxy_has_glx'

The NetBSD-current test run was on a freshly installed OS, using a
pkgsrc.tar.gz from ftp.netbsd.org with a timestamp of Oct 27 02:14
UTC.  In an earlier test on NetBSD-current where I accidentally used
the pkgsrc.tar.gz from Oct 20, emacs25 built successfully, so the
problem must have been introduced in the meantime, perhaps by
gtk3+-3.24.1.

Riccardo Mottola reported the same problem but with emacs26, on -current:

  http://mail-index.netbsd.org/current-users/2018/10/23/msg034424.html

In the ensuing discussion, Greg Troxel asked:
> And did it build libepoxy in this case?

Yes, both with the Oct 20 and the Oct 27 pkgsrc.  With the Oct 20
pkgsrc, the log from building emacs25 from scratch contains:

  => Returning to build of gtk3+-3.22.30nb3
  [...]
  => Full dependency libepoxy>=1.2nb2: NOT found
  [...]
  => Fetching libepoxy-1.4.3.tar.gz

and with the Oct 27 pkgsrc:

  => Returning to build of gtk3+-3.24.1
  [...]
 => Full dependency libepoxy>=1.4: NOT found
  [...]
  => Fetching libepoxy-1.4.3.tar.gz

Only in the latter case does /usr/pkg/lib/libgdk-3.so contain a
reference to epoxy_has_glx.

Comparing gtk3/work/.work.log between the two pkgsrc versions, the
first line mentioning epoxy in the Oct 20 one is

  [*] /usr/pkgsrc/x11/gtk3/work/.tools/bin/pkg-config --exists --print-errors pango pangocairo gdk-pixbuf-2.0 >= 2.30.0 cairo >= 1.14.0 cairo-gobject >= 1.14.0 gio-unix-2.0 >= 2.49.4 fontconfig x11 xext xinerama xi xrandr xcursor xfixes xcomposite xdamage    cairo-xlib epoxy >= 1.0

and in the Oct 27 one:

  [*] /usr/pkgsrc/x11/gtk3/work/.tools/bin/pkg-config --exists --print-errors pango pangocairo gdk-pixbuf-2.0 >= 2.30.0 cairo >= 1.14.0 cairo-gobject >= 1.14.0 gio-unix-2.0 >= 2.53.4 fontconfig x11 xext xinerama xi xrandr xcursor xfixes xcomposite xdamage    cairo-xlib epoxy >= 1.4 

>How-To-Repeat:

>Fix: