tractor/tractor/spawn
Gud Boi 40e2916b8b Raise `subint` floor to py3.14 and split dep-groups
The private `_interpreters` C module ships since 3.13, but that vintage
wedges under our `threading.Thread` + multi-trio usage pattern
—> `_interpreters.exec()` silently never makes progress. 3.14 fixes it.
So gate on the presence of the public `concurrent.interpreters` wrapper
(3.14+ only) even tho we still call into the private module at runtime.

Deats,
- `try_set_start_method('subint')` error msg + `_subint` module
  docstring/comments rewritten to document the 3.14 floor and why 3.13
  can't work.
- `_subint._has_subints` gate now imports `concurrent.interpreters` (not
  `_interpreters`) as the version sentinel.

Also, reshuffle `pyproject.toml` deps into
per-python-version `[tool.uv.dependency-groups]`:
- `subints` group: `msgspec>=0.21.0`, py>=3.14
- `eventfd` group: `cffi>=1.17.1`, py>=3.13,<3.14
- `sync_pause` group: `greenback`, py>=3.13,<3.14
  (was in `devx`; moved out bc no 3.14 yet)

Bump top-level `msgspec>=0.20.0` too.

(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code

(cherry picked from commit 34d9d482e4)
(MTF-only portion: kept tractor/spawn/_spawn.py tractor/spawn/_subint.py)
2026-06-22 14:53:31 -04:00
..
__init__.py Restore fn-arg `_runtime_vars` in `trio_proc` teardown 2026-04-23 18:30:11 -04:00
_entry.py Tidy `spawn/` subpkg docstrings and imports 2026-04-17 19:03:00 -04:00
_forkserver_override.py Mv core mods to `runtime/`, `spawn/`, `discovery/` subpkgs 2026-04-02 17:59:13 -04:00
_mp.py Tidy `spawn/` subpkg docstrings and imports 2026-04-17 19:03:00 -04:00
_mp_fixup_main.py Fix typos + typing in `_mp_fixup_main` 2026-04-10 20:58:54 -04:00
_reap.py Add `tractor.spawn._reap.unlink_uds_bind_addrs()` 2026-06-17 17:39:44 -04:00
_spawn.py Raise `subint` floor to py3.14 and split dep-groups 2026-06-22 14:53:31 -04:00
_subint.py Raise `subint` floor to py3.14 and split dep-groups 2026-06-22 14:53:31 -04:00
_trio.py Add `tractor.spawn._reap.unlink_uds_bind_addrs()` 2026-06-17 17:39:44 -04:00