As a developer (and not only), it is convenient many times to do short testing sessions without the need to completely install Kamailio.
You can run it from the top directory where you keep Kamailio's source tree.
Compile as usual:
make FLAVOUR=kamailio cfg make all
Then set mpath in your configuration file to be:
And run Kamailio:
./kamailio -f /path/to/your/config/file
Default configuration file has a define switch that allows to run from source tree directory, the command is:
./kamailio -f etc/kamailio.cfg -A WITH_SRCPATH
If you want to run it in debugging mode (print logs to terminal and be verbose), you can use:
./kamailio -f etc/kamailio.cfg -A WITH_SRCPATH -E -ddd