[SR-Users] how to debug kamailio c code

I have issue with kazoo module call sprintf <https://github.com/kamailio/kamailio/blob/master/src/modules/kazoo/kz_pua.c#L254> not work properly. body variable contains values like \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 Must be XML string <?xml version="1.0" encoding="UTF-8"?><presence xmlns="urn:ietf:params:xml:ns:pidf" xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model" xmlns:rpid="urn:ietf:params:xml:ns:pidf:rpid" xmlns:c="urn:ietf:params:xml:ns:pidf:cipid" entity="2496"> <tuple xmlns="urn:ietf:params:xml:ns:pidf" id="t8No1hQnp65U33jS1oqFMgxbIRPq-iFP"><status><basic>open</basic></status></tuple><note xmlns="urn:ietf:params:xml:ns:pidf">On the Phone</note><dm:person xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model" xmlns:rpid="urn:ietf:params:xml:ns:pidf:rpid" id="1"><rpid:activities><rpid:on-the-phone/></rpid:activities><dm:note>On the Phone</dm:note></dm:person></presence> But i cannot find/understand where is must be executed conversion hex2string I want use gdb inspect memory vars but i cannot. Please advice how to do it.