I'm guessing that Ubuntu has broken libtool by not automatically adding
dependent libraries from the .la file...
$(FREETYPE_CFLAGS) \
$(X_CFLAGS)
-# libpangoxft.la and/or libpangocairo.la pull in libpango.la
-# and libpangoft2.la;
# We're assuming here that we'll only regenerate the
# HTML docs on Unix. We don't get introspection on Win32
# specific types, but that isn't a big deal.
-GTKDOC_LIBS =
+GTKDOC_LIBS = $(top_builddir)/pango/libpango-1.0.la
+
+if HAVE_FREETYPE
+GTKDOC_LIBS += $(top_builddir)/pango/libpangoft2-1.0.la
+endif
if HAVE_XFT
GTKDOC_LIBS += $(top_builddir)/pango/libpangoxft-1.0.la