This is a valid patch. However, I'm almost done with porting Avro C++ to Miscrosoft Windows. CMake + Windows + Flex/Bison appear to be a problem combination. Moreover, the Schema parser based on Flex/Bison is not complete and produces no good error messages. I've implemented a new parser on top of Json parser we already have in Avro C++. We can then implement full compliance to Avro standard including namespaces, docs etc.
I'll file 2 Jiras one for getting rid of dependence on flex/bison and BoostRegex and another for porting to Microsoft Windows. With those patches we don't have to fix the Flex/Bison find problems.