Hello, The configmake module uses AC_SUBST for pkglibexecdir, which overrides Automake's default definition. If gl_CONFIGMAKE_PREP isn't run then the substituted value is empty.
This was a problem with Texinfo, reported here: http://lists.gnu.org/archive/html/bug-texinfo/2016-01/msg00046.html Maybe the assignment could be made unconditionally, or removed. Thanks, Gavin