Dropping the `_maybe_open_repl_fixture()` approach and instead using
a `DebugStatus._fixture_stack = ExitStack()` which provides for much
simpler support around both sync and async pausing APIs thanks to only
invoking `repl_fixture.__exit__()` on actual `PdbREPL` interaction being
complete!
Deats,
- all `repl_fixture` detection logic still happens in one place (the new
method) but we aren't limited to closing it via an immediate post REPL
`.__exit__()` call which instead is triggered by,
- `DebugStatus.release()` which now calls `._fixture_stack.close()` and
thus only invokes `repl_fixture.__exit__()` when user REPL-ing is
**actually complete** an arbitrary amount of debugging time later.
- include the notes for `@acm` support above the new method, though not
sure if they're as relevant any more?
Benefits,
- we can drop the previously added indent levels from
`_enter_repl_sync()` and `_post_mortem()`.
- now we automatically have support for the `.pause_from_sync()` API
since `_enter_repl_sync()` doesn't close the prior
`_maybe_open_repl_fixture()` immediately when `debug_func=None`; the
user's `__exit__()` is only ever called once `.release()` is.
Other,
- add big 'CASE' comments around the various blocks in
`.pause_from_sync()`, i was having trouble figuring out which i was
using from a `breakpoint()` in a dependent app..
a5126862b9