Hello, Your package inherits cmake-utils.eclass and makes a direct call to a base.eclass function without inheriting base.eclass. Since cmake-utils.eclass no longer inherits base, this could cause breakage. Please check your package and either inherit base or make sure that you are implicitly inheriting base.eclass through some other eclass. It may be worthwhile to add the base.eclass inherit even if you already have it inherited through another eclass. Thanks!
Alternatively, cmake-utils now exports src_prepare which should be able to replace the base_src_prepare call entirely. Apologies for not mentioning this in the initial report.
Fixed in CVS.