The default recipe incudes this line:
include_recipe "mysql::client" if node[:sphinx][:use_mysql]
The mysql cookbook was refactored in version 4.0 to implement server and client as resources rather than recipes, so for mysql cookbook >= 4.0, the client recipe does not exist.
A reasonable solution might be to simply remove that include_recipe statement and document that you have to have a client installed first. (I have not tested this, but our workaround is to just install the unixodbc, libpq5, and sphinxsearch packages so it seems ok.)