[OE-core] [PATCH 1/2] lttng-tools ptest: add missing dependencies

[Jonathan Rajotte-Julien]

> Since the patches with a couple of fixes were passing the tests, I've
> merged the patches with the glibc/muslc tweak and also a tweak to make
> disabled ust work. I'd normally wait for v2 resubmission but I wanted
> to get this fix into M3 and the M3 build is already behind schedule.

Sounds good.

> 
> I was at a conference last week so a bit distracted, just catching up
> now.
> 
> > Also, I saw that lttng-ust is removed from PACKAGECONFIG when using
> > musl, not sure why the commit history is not particularly verbose
> > regarding why it was a problem. Still, it seems to build fine but we
> > are seeing issue regarding musl.
> 
> I think when we originally merged musl, lttng didn't build with it or
> there were some kind of issues. I suspect lttng-ust still doesn't work
> on all the architectures we build for so we likely need to be able to
> optionally disable it. I'd be happy to see patches enabling it where it
> does work though.

Well lttng-ust does work on musl as long as users do not fiddle with
sched_affinity... I cc'ed you on the musl thread about this [1].

[1] https://www.openwall.com/lists/musl/2019/03/15/5

For now we can leave the disable statement there. We will revisit when musl is
fixed and/or when lttng-ust have a fallback (most likely to happen) when using
musl.

> 
> 
> > We checked with Alpine since they also use musl and see similar
> > problem. I'm investigating on that front. I'll let you know what I
> > find.

See [1].

We also found a dynamic linker problem on our side for the notification test.
We will upstream it in the following weeks.

> > 
> > Side note, gdb simply segfault (at start) for me on a core-image-
> > minirmnal build using musl.
> > How would someone open the corefile generated on the build system
> > with the proper libs and all?
> 
> I saw other discussion about this so it looks like you're making
> progress on this front. If not, Khem would be the person to ask about
> this as our musl expert...

Do you have a link to said discussion? I ended up debugging using print
statement since even on Alpine gdb is "broken" (not working as expected). 
I'm not sure how much time I can use on this. Will let you know if any progress
is made to at least get a backtrace for the gdb coredump.

Thanks again!

-- 
Jonathan Rajotte-Julien
EfficiOS