On Wed, 27 Apr 2016 14:52:36 +0200
ludo@gnu.org (Ludovic Courtès) wrote:

> Kei Yamashita <kei@openmailbox.org> skribis:
> 
> > This patch is in preparation for the Dillo browser package.
> >
> > From 7755ae6d7afd46daed5fac1e626d1785b9875975 Mon Sep 17 00:00:00
> > 2001 From: Kei Yamashita <kei@openmailbox.org>
> > Date: Sat, 16 Apr 2016 22:45:21 -0400
> > Subject: [PATCH] gnu: Add Xft support to FLTK.
> >
> > * gnu/packages/fltk.scm (fltk)[inputs]: Add libxft.  
> 
> This appears to break Octave (see
> <https://hydra.gnu.org/log/gx7z8zd3x113605gpnjp6adx98qwy9fy-octave-4.0.0>):
> 
> --8<---------------cut here---------------start------------->8---
> ../run-octave  --norc --silent --no-history ./fntests.m .
> error: /tmp/guix-build-octave-4.0.0.drv-0/octave-4.0.0/libinterp/dldfcn/PKG_ADD: /tmp/guix-build-octave-4.0.0.drv-0/octave-4.0.0/libinterp/dldfcn/__init_fltk__.oct:
> failed to
> load: /gnu/store/nfi0na44lk0fy0m6bpsa7q458wpyd5w5-fltk-1.3.3/lib/libfltk_gl.so.1.3:
> undefined symbol: _ZN18Fl_XFont_On_Demand5valueEv
> --8<---------------cut here---------------end--------------->8---
> 
> The undefined symbol (demangled: ‘Fl_XFont_On_Demand::value’) is
> defined in Fltk’s ‘fl_font_xft.cxx’.  However, looking at the build
> log of Fltk, this file is apparently not compiled, which sounds like
> a bug in Fltk’s build system.
> 
> Could you look into it?
> 
> Thanks in advance.  :-)
> 
> Ludo’.

You could try this patch. I switched on a configure flag that
supposedly enables Xft support. I tried rebuilding Octave locally with
the new FLTK, but my machine wasn't powerful enough so it started
heavily swapping memory to disk.