I built the kernel with all debug options and diagnostics.. and the
crashes disappeared.

On the other hand with these options enabled "resume1" started to fail,
a test from our ATF regression unit tests in t_ptrace_wait*.

There are two bugs:
1. kernel crashes with threads in the local copy of Process Plugin.
2. PT_SUSPEND, PT_RESUME unreliable http://gnats.netbsd.org/51995

I'm working on (1.) now.

If possible please help with (2.) as there are ATF tests ready and no
need to setup LLVM+Clang+LLDB.


I had to downgrade llvm/clang/lldb to pkgsrc-wip r. cf22065aaf016 to
reproduce the crash again (LLVM SVN r.300853). It was hidden with recent
failures for 400 tests for some other unknown reason.

The crash has been fixed with src/sys/kern/sys_ptrace_common.c r1.22

I'm still verifying single stepping of LWPs in processes with multiple
threads. I have an impression that something is fragile there.

LLDB tests trigger dmesg errors (default GENERIC kernel), there are
entries like:
fill_vmentry: vp 0xfffffe87288967e8 error 2
fill_vmentry: vp 0xfffffe86e1a15930 error 2
fill_vmentry: vp 0xfffffe87047f8bd8 error 2
fill_vmentry: vp 0xfffffe87051af7e0 error 2
fill_vmentry: vp 0xfffffe86ef0b63f0 error 2

Once the above points will be so sorted out, I will move to the recent
failure that broke tests in LLDB on NetBSD. And next I will work on
watchpoint misbehavior (they are reported like PT_STEP).

Additionally something (related?) recently keeps ejecting the NetBSD
builder in the farm node as it timeouts (?).

We need to sort out all that before pushing forwards the NetBSD Process
Plugin with threads in LLDB.