Disclaimer. I have no experience with this Poco library.
Without further details on your environment or your tools... I can only provide some very general advice:
How I'd chase this is:
- Locate in what library or object file are defined the symbols reported as undefined symbols. On unix-like environments this can be achieved with the nm tool
- Verify that the libraries or objects are compiled on the right architecture (I see you're using x86_64) file tool might help you there
- Verify that you're referring to the library in the linker command line (look for a -l for dynamic or static libraries) or that you're including the object file or the static library in the list of things to link.
- Verify that you're referring to the right library (either through -L flags or the LD_LIBRARY_PATH env variable (or LD_LIBRARY_PATH_64 in some systems e.g. Solaris for 64bits build)
I know you said you have linked the Poco libraries, but the error is clearly that a symbol is missing. Either the library is missing or you need to fiddle with the order of the -l flags to satisfy the dependencies. The nm might help you there in determining what objects or libraries refer to the symbol (must come first) and what objects or libraries define the symbol (must come later).
Sorry not being of more help.
P.S. In addition you might want to look at Linking error with Poco Net which might be related.
One more reference to a question that details different causes for linker errors: What is an undefined reference/unresolved external symbol error and how do I fix it?