Created attachment 808 [details]
libsdl-ttf2.0-glyph_error_reporting.patch

Debian contains the following bug report with a patch attached since a while ago, but I think that the upstream code still lacks these fixes/suggestions, so  I don't think that it has been reported upstream.  Anyway, it seems appropriate and useful to me to forward the bug report and patch.

http://bugs.debian.org/405378

  Package: libsdl-ttf2.0-0
  Version: 2.0.8-3+b1

  I was just bitten by bug 374062 (any word if this will be fixed for
  etch given that it is fixed upstream?), and found that there is no
  error message set by sdl-ttf when it is unable to render a glyph,
  which makes bugs like this a bit more difficult to track down.  I
  would really appreciate it if TTF_GetError() could return a useful
  message in such situations.  The attached patch does just that by
  duplicating the existing error reporting for calls to Find_Glyph()
  into the places where it is missing, although it might be nice to know
  which glyph it was that could not be found...

The patch might be a bit out of date so maybe it doesn't apply cleanly, but that should be easy to fix if you're interested in incorporating it.