Bug #427
closed
Misleading message from lttng command when modules not loaded
Added by Daniel U. Thibault over 11 years ago.
Updated over 11 years ago.
Description
If you issue the 'lttng' command while the lttng modules are not loaded, the misleading error message is:
lttng: error while loading shared libraries: liblttng-ctl.so.0: cannot open shared object file: No such file or directory
This initially makes the user think that the liblttng-ctl.so.0 symbolic link is damaged, or that the lttng-tools installation is otherwise damaged. Ideally lttng should check for the lttng kernel modules (lttng-tracer should suffice, I suspect) and report their absence.
- Status changed from New to Invalid
This has nothing to do with the lttng-modules not being loaded.
Make sure that you have issued the 'sudo ldconfig' command after installing the lttng-tools.
Thanks,
Christian
(I'll add my response anyway)
This means that "lttng" command does not find the liblttng-ctl so two possibilities. Either it's not installed or the "ldconfig" command was not done.
Please make sure you can find liblttng-ctl.so in either /usr/lib or /usr/local/lib.
Flagging this invalid because this is a system message not related to the lttng UI nor related to lttng modules. There is an install problem on your side. Please note that "ldconfig" is NOT executed by doing make install from the git tree and this is desired.
Thanks
I was going to withdraw the bug report anyway, since I can't reproduce it anymore, oddly enough.
However, you're nevertheless both missing the point. I was not asking that the lttng-modules be loaded or installed, I was reporting a misleading error message which the lttng command issued because the modules were not loaded.
Had this bug been reproducible, the misleading error message should have been addressed, not dismissed. Even an incorrect installation should, ideally, be diagnosed as such for the user.
What message issued by lttng ? This?
lttng: error while loading shared libraries: liblttng-ctl.so.0: cannot open shared object file: No such file or directory
"Flagging this invalid because this is a system message not related to the lttng UI..."
The lttng command DOES NOT print that and we have no control over that. Installing the lttng-tools packages from a distribution should NOT show this error. However, from the git tree, it means a missing ldconfig command or that the lib is simply not installed.
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