[lldb-dev] Debugging lldb with lldb: infinite process interrupt?

[Greg Clayton via lldb-dev]

> On Oct 27, 2015, at 11:18 AM, Ramkumar Ramachandra via lldb-dev <lldb-dev at lists.llvm.org> wrote:
> 
> Hi,
> 
> I'm using lldb to debug lldb, and I notice that I get this message in
> the inner lldb:
> 
> (lldb) p F
> error: Process is running.  Use 'process interrupt' to pause execution.
> 
> If I 'process interrupt', I go to the outer lldb (presumably), and if
> I try to 'continue', the same message is displayed over and over
> again.
> 
> This only happens _sometimes_, and I can't quite explain when.
> 
> Any clues?

Sometimes processes that are in the same process group will forward signals to each other if it isn't handled. Interrupting the process usually sends a SIGSTOP or SIGINT to the process and that may be being forwarded up to the current LLDB somehow.

If you are debugging two LLDB binaries I would start one in one terminal and attach to it from another terminal running LLDB so you don't have to share the same terminal. This will ensure the two processes aren't in the same process group and no signals will be forwarded.

I sometimes do debug one LLDB with another and when I do this, I set my prompt to "(lldb-top) ":

(lldb) settings set prompt "(lldb-top) "
(lldb-top) 

Then I can tell the two apart.