2013/3/8 Bert Freudenberg <bert at freudenbergs.de>:
>
> On 2013-03-08, at 10:55, Frank Shearar <frank.shearar at gmail.com> wrote:
>
>> On 7 March 2013 23:25, Frank Shearar <frank.shearar at gmail.com> wrote:
>>> On 7 March 2013 23:11, Bert Freudenberg <bert at freudenbergs.de> wrote:
>>>> On 2013-03-07, at 23:42, Frank Shearar <frank.shearar at gmail.com> wrote:
>>>>
>>>>>>> On 6 March 2013 15:59, Ken G. Brown <kbrown at mac.com> wrote:
>>>>>>>> Running on COG 2397, and after updating fresh Squeak4.4-12327 Release to
>>>>>>>> 12332, updating to Trunk  fails at first attempt in the same place, then by
>>>>>>>> abandoning and trying the update again, it apparently completes to 12511.
>>>>>>>>
>>>>>>>>  Ken G. Brown
>>>>>>>>
>>>>>>>>> With COG 2678, pretty well the same. First attempt it timed out during
>>>>>>>>> the same update-nice-223, then trying again from what had already been
>>>>>>>>> loaded, got the following during the same update, during compiling
>>>>>>>>> SMLoader-fbs-78 as before:
>>>>>
>>>>> What I find strange about all this is that we take a 4.4-12327 image
>>>>> and whatever the latest Cog is and update it all the way without any
>>>>> probems quite a few times a day on the CI server.
>>>>>
>>>>> frank
>>>>
>>>> Looks like it's an intermittent problem, unfortunately:
>>>>
>>>> I just updated the new all-in-one-cog to latest trunk, no problem. This is a 4.4-12327 image with Cog VM 2697.
>>>>
>>>> I then tried what Ken described: update the fresh image first from the squeak44 stream, then switch to trunk, then update again.
>>>>
>>>> BOOM. Cog crash. Didn't save the log unfortunately.
>>>>
>>>> Tried again. Update, switch to trunk, update again. No crash. What?!
>>>>
>>>> Once more. Update, switch to trunk, update. Crash! See below.
>>>>
>>>> Tried yet again, with switching to trunk immediately in a fresh image. Crashes, too, same place.
>>>>
>>>> So it does crash, just not always. But it's been more than 50% in my case.
>>>
>>> Ah, interesting. The CI jobs, naturally, don't update from squeak44;
>>> they switch to trunk and update just like that. Which I would have
>>> thought would make no difference...
>>
>> Actually, I lie. Here's an example of the CI jobs hitting the same
>> issue: http://build.squeak.org/job/SqueakTrunk/204/console And further
>> if you look at http://build.squeak.org/job/SqueakTrunk/ and choose to
>> see the failing tests you'll see times (say around build #184) where
>> the test failure count is unusually low. And
>> http://build.squeak.org/job/SqueakTrunk/buildTimeTrend shows grey
>> streaks where builds die.
>
> Curious that it still runs the tests at all if the update failed ...
>
> So Cog crashes, but has someone tried to replicate this on an interpreter?
>
> - Bert -
>

I think that the problem comes form COG which tries to use an obsolete
method sent AFTER the recompilation of Parser which is not the
expected behavior.
I have triggered such kind of strange behavior that does not happen on
an Interpreter VM, see the thread opened by Jeff Gonis '[Vm-dev] Cog
VM Crash on Windows'
For me, it must be related to a cache that is not cleaned-up, I don't know why.

Nicolas