Why I can't trace linux process's childs with truss?

[Alexander Best]

On Fri Sep 10 10, Jilles Tjoelker wrote:
> On Fri, Sep 10, 2010 at 12:07:05PM -0700, Yuri wrote:
> > I am trying to get the log of all system calls that skype makes with 
> > truss -f /usr/local/share/skype/skype
> > For some reason the resulting log only has the leading process calls and 
> > nothing from it's 8 childs.
> > Truss doesn't show any 'cloned' processes. Is this a bug in truss that 
> > it doesn't follow 'cloned' processes?
> 
> > Is there any workaround or other way I can debug skype? strace doesn't 
> > work on amd64.
> > I am primarily interested why it can't read /dev/video0 device, created 
> > by webcamd.
> 
> Try using ktrace instead of truss. You will need devel/linux_kdump from
> ports to decode the resulting ktrace.out.

there's a PR related to this "issue" [1]. so is truss missing this
functionality or is this in fact a feature, because truss musn't be used on
any non freebsd executable?

if that is the case i vote to add a CAVEATS section to the truss(1) manual so
people rather use ktrace in combination with linux_kdump.

cheers.
alex

[1] http://www.freebsd.org/cgi/query-pr.cgi?pr=150262

> 
> Alternatively, if you're familiar with dtrace, you could try that.
> 
> -- 
> Jilles Tjoelker

-- 
a13x