LTTng » LTTng-tools

Running the example provided in the release notes (https://github.com/lttng/lttng-tools/releases/tag/v2.11.0-rc1), I believe I found a bug when setting a custom trace output path.

The following worked as expected. The trace was written to the default location (lttng-traces/demo-session-<timestamp>).

sudo lttng create demo-session
sudo lttng enable-event --kernel --userspace-probe /lib/x86_64-linux-gnu/libc-2.23.so:malloc libc_malloc
sudo lttng start

[do various actions]

sudo lttng stop
sudo lttng destroy

The following resulted in no trace file being produced:

sudo lttng create demo-session --output=/tmp/demo-session
sudo lttng enable-event --kernel --userspace-probe /lib/x86_64-linux-gnu/libc-2.23.so:malloc libc_malloc
sudo lttng start

[do various actions]

sudo lttng stop
sudo lttng destroy

The problem also applied if I set it to use the default directory:

sudo lttng create demo-session --output=/lttng-traces/demo-session
sudo lttng enable-event --kernel --userspace-probe /lib/x86_64-linux-gnu/libc-2.23.so:malloc libc_malloc
sudo lttng start

[do various actions]

sudo lttng stop
sudo lttng destroy

I am expecting to be able to set a custom output path based on the 2.10 documentation (https://lttng.org/docs/v2.10/#doc-tracing-the-linux-kernel)
I made sure to do exactly the same actions for each test.