Bug#561681: crashes on startup

[Dave Beckett]

Adrian Knoth wrote:
> On Sat, Dec 19, 2009 at 05:02:21PM +0100, hungerburg wrote:
> 
> Hi!
> 
>> the last time I used ardour two days ago. I believe it was
>> 1:2.8.4-1 - today after updating to 1:2.8.4-2 I can no longer
>> launch the application. A downgrade does not help. Maybe its
>> because a file changed that ardour uses but that is in another
>> package.
> 
> We have to sort things out. I claim that it's not an ardour bug,
> ardour's working fine over here and you say that downgrading doesn't fix
> the bug, so it's very likely not ardour's fault.
> 
> I'll reassign the bug to the appropriate package once we know the
> culprit.
> 
>> Below valgrind output shows an invalid memory access while
>> loading lv2 plugins. I am not aware that debian ships any of
>> those though or that such plugins are installed on this
>> system here.
> 
> We do have LV2 plugins in Debian, however, ardour's LV2 code is rather
> stable. See below.
> 
>> ==29391== Jump to the invalid address stated on the next line
>> ==29391==    at 0xC: ???
>> ==29391==    by 0x58CEF8F: rasqal_engine_execute_init (in /usr/lib/librasqal.so.1.0.0)
>> ==29391==    by 0x58CA128: rasqal_query_execute (in /usr/lib/librasqal.so.1.0.0)
>> ==29391==    by 0x58A8781: ??? (in /usr/lib/librdf.so.0.0.0)
>> ==29391==    by 0x58A5D49: librdf_query_execute (in /usr/lib/librdf.so.0.0.0)
>> ==29391==    by 0x595A83D: slv2_world_load_specifications (in /usr/lib/libslv2.so.9.2.0)
>> ==29391==    by 0x595AE93: slv2_world_load_all (in /usr/lib/libslv2.so.9.2.0)
>> ==29391==    by 0x424E262: ARDOUR::LV2World::LV2World() (in /usr/lib/ardour2/libardour.so)
>> ==29391==    by 0x4198453: ARDOUR::PluginManager::PluginManager() (in /usr/lib/ardour2/libardour.so)
>> ==29391==    by 0x41462D0: ARDOUR::init(bool, bool) (in /usr/lib/ardour2/libardour.so)
>> ==29391==    by 0x816080C: ARDOUR_UI::ARDOUR_UI(int*, char***) (in /usr/lib/ardour2/ardour-2.8.4)
>> ==29391==  Address 0xc is not stack'd, malloc'd or (recently) free'd
> 
> Here we go. As always, stack traces are bottom up. We see that ardour
> calls some LV2 functions which are handled by libslv2. This library does
> the whole LV2 discovery stuff.
> 
> Further up the stack trace, we see librdf executing a query, which is
> then passed to librasqal.
> 
> Both libs, librdf and librasqal, have new versions in unstable since
> yesterday, so I guess one of them is the culprit:
> 
>    http://packages.qa.debian.org/r/redland.html
> 
>    http://packages.qa.debian.org/r/rasqal.html
> 
> (new versions on 2009-12-17)
> 
> 
> When I downgrade librdf0 to 1.0.9-3, ardour starts fine.
> 
> 
> That's why I would say librdf0 is the real culprit here.
> 
> I'm now building ardour against new librdf0 to see if this fixes the
> issue, but I don't think so. (libs are expected to be backward
> compatible, that is, ardour built against librdf0-1.0.9 should run with
> librdf0-1.0.10.
> 
> 
> However, I'll CC the librdf0 maintainer, so he has the chance to do some
> investigations himself.
>