On Fri, 2018-02-23 at 00:16 +0000, Cheryl Sabella wrote:
> Cheryl Sabella <chekat2@gmail.com> added the comment:
> 
> Did PEP553 make this issue obsolete?

I *think* they have slightly different scope: if I'm reading it right,
PEP553 is about injecting a breakpoint into the Python debugger.  This
proposal was about injecting a lower-level breakpoint for debugging
CPython itself (for e.g. gdb to handle).

The idea was to make it easier to, say, step through a particular
CPython construct at the C level by injecting a breakpoint right before
it:

def test_something():
  # lots of setup
  sys.c_level_breakpoint()
  # whatever comes next

so that sys.c_level_breakpoint drops you into, say, gdb, and from there
you can step through the following Python code at the C level, without
having to express stepping through all the setup at the C/gdb level.

Hope that makes sense.

That said, I'm full-time on gcc these days, and unlikely to pursue this
from the CPython side.