Poco libraries missing methods

[mkaut]

Building the following code (saved as test.cpp):

#include <Poco/Data/MySQL/Connector.h>
int main() {
	Poco::Data::MySQL::Connector::registerConnector();
	std::string conType = Poco::Data::MySQL::Connector::KEY;
	return 0;
}

using g++ -o test.exe test.cpp -lPocoDataMySQL -lmysqlclient -lPocoData fails with:

C:\Users\mkaut\Apps\MSYS2\tmp\ccAPijGz.o:test.cpp:(.text+0x14): undefined reference to `Poco::Data::MySQL::Connector::registerConnector()'
C:\Users\mkaut\Apps\MSYS2\tmp\ccAPijGz.o:test.cpp:(.rdata$.refptr._ZN4Poco4Data5MySQL9Connector3KEYB5cxx11E[.refptr._ZN4Poco4Data5MySQL9Connector3KEYB5cxx11E]+0x0): undefined reference to `Poco::Data::MySQL::Connector::KEY[abi:cxx11]'
collect2.exe: error: ld returned 1 exit status

On closer inspection, the supplied library libPocoDataMySQL.dll.a lacks both Poco::Data::MySQL::Connector::registerConnector() and Poco::Data::MySQL::Connector::KEY.
By the way, these are present in libPocoDataSQLite.dll.a, but missing also in libPocoDataODBC.dll.a.

This is on fully-updated MSYS-2, using mingw64 gcc and libraries.