speex.m4 : syntax error
autoconf 1.8 is stricter than older revisions. it warns about a syntax error :
/usr/share/aclocal/speex.m4:10: warning: underquoted definition of XIPH_PATH_SPEEX
AC_DEFUN(XIPH_PATH_SPEEX, => AC_DEFUN([XIPH_PATH_SPEEX],
would fix it