Bug 21823 - SGEN Assertion: should not be reached at sgen-scan-object.h:111
Summary: SGEN Assertion: should not be reached at sgen-scan-object.h:111
Alias: None
Product: Runtime
Classification: Mono
Component: GC ()
Version: unspecified
Hardware: Macintosh Mac OS
: High normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2014-08-05 11:10 UTC by Sean Pearl
Modified: 2015-11-03 17:12 UTC (History)
4 users (show)

Is this bug a regression?: ---
Last known good build:

Stacktrace and GDB (3.67 KB, text/plain)
2014-08-05 11:10 UTC, Sean Pearl

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Description Sean Pearl 2014-08-05 11:10:58 UTC
Created attachment 7586 [details]
Stacktrace and GDB

We hit this somewhat intermittently after an nunit test case completes. 

Expected: Clean exit.

Actual: Attached, mono-sgen processes on the target machine do not exit.

gdb does not provide useful output.

Cannot repro on the target machine with test cases from https://bugzilla.xamarin.com/show_bug.cgi?id=13813 or https://bugzilla.xamarin.com/show_bug.cgi?id=14339
Comment 1 Mark Probst 2014-08-06 12:34:15 UTC
Can you confirm that the crash occurs on mono master?

Could you provide a test case?
Comment 2 Sean Pearl 2014-08-11 15:15:33 UTC
The issue is (seemingly) sporadic enough that I haven't been able to capture it in a test case yet, but it is constantly blocking cycle testing.

I'm running with recent builds of the 3.6 and 3.8 branches of mono. I may need to find a runtime team member to help diagnose if it continues blocking.
Comment 3 Mark Probst 2014-08-11 17:09:02 UTC
Would you mind checking if the bug persists if you use the environment variable


for mono?
Comment 4 Sean Pearl 2014-08-14 15:10:10 UTC
Mono doesn't seem to think that's a legitimate option.

>Runtime Environment - 
>   OS Version: Unix
>  CLR Version: 2.0.50727.1433 ( Mono 3.5 ( 3.8.0 ((no/62a857e Wed Aug 13 00:46:20 EDT 2014) ) )
>ProcessModel: Default    DomainUsage: Single
>Execution Runtime: mono-3.5
>Warning: In environment variable `MONO_GC_PARAMS': Unknown option `clear-at-gc`. - Ignoring.
Comment 5 Mark Probst 2014-08-14 16:33:12 UTC
I'm sorry, it's MONO_GC_DEBUG, not MONO_GC_PARAMS.
Comment 6 Alexis Christoforides 2015-11-03 17:12:55 UTC
Hi Sean, I'm closing this bug as it applies to an older version of Mono. Feel free to reopen if you come across the same problem in our 4.0 or 4.2 releases.