[lldb-dev] Unreliable process attach on Linux

[Florian Weimer via lldb-dev]

* Jan Kratochvil:

> On Fri, 04 Jan 2019 17:38:42 +0100, Florian Weimer via lldb-dev wrote:
>> Run it in a loop like this:
>> 
>> $ while ./test-attach ; do date; done
>> 
>> On Linux x86-64 (Fedora 29), with LLDB 7 (lldb-7.0.0-1.fc29.x86_64) and
>> kernel 4.19.12 (kernel-4.19.12-301.fc29.x86_64), after 100 iterations or
>> so, attaching to the newly created process fails:
>> 
>> test-attach: SBTarget::Attach failed: lost connection
>
> FYI after 30000 runs it still runs fine with your reproducer both with system
> lldb-devel-7.0.0-1.fc29.x86_64 and COPR
> lldb-experimental-devel-8.0.0-0.20190102snap0.fc29.x86_64 (=trunk), part
> running without /usr/lib/debug and part with.

Well, that's odd.  Shall I try to reproduce this on a lab machine?

> Fedora 29 x86_64 + kernel-4.19.10-300.fc29.x86_64
>
> (I haven't investigated the code why it could fail this way.)

First, I want to get more logging data out of LLDB.  Maybe this will
tell us where things go wrong.

Thanks,
Florian