If one generates an interface into a different package than the source package, e.g.:

ifacemaker -f ../bindings.go -s MyStruct -o i_mystruct.go -p interfaces -i IMyStruct

Then the generated code may be invalid if any of the method signatures contain custom types defined in the source package, e.g.: the generated code in the interfaces package references a custom type defined in the source package as MyType instead of importing from the source package and refering to it as bindings.MyType