error reporting when kernel tracing not available because of a version mismatch between tools and modules
If lttng-modules and lttng-tools versions don't match, an error is only reported when starting the sessiond, after that all commands seem to succeed but fail silently.
So if the sessiond is started by a startup script, the user never knows kernel tracing is not working.
Also, the error message is not very accurate: "Error: Kernel tracer ABI version (2.0) is not compatible with expected ABI major version (1.*)"
root@asdf:~# lttng create
Session auto-20151008-092032 created.
Traces will be written in /home/asdf/lttng-traces/auto-20151008-092032
root@asdf:~# lttng enable-event -k -a
All Kernel events are enabled in channel channel0
this should fail ^