Is the exec_avp() used in a failure_route block?
Can you get from the core file the output for the next gdb commands:
``` list info locals p t p *t p *t->uas.request p faked_req p *faked_req ```
Do you need the output of the shell command? If not, you can run it with the option to go in background, so there is no blocking waiting for the shell command to complete, like:
``` exec_avp("/usr/bin/zabbix_sender --config ZABBIX_AGENT_CONFIG_PATH --key ecsp_no_telephony --value 1 &"); ```