bpo-28254: _posixsubprocess uses PyGC_Enable/PyGC_Disable by vstinner · Pull Request #25693 · python/cpython

Actually, I think much of this could already have been saved before by using the ID-string API. But still, this is just so much better.

I don't think that using cached interned strings is really relevant here, spawning a subprocess takes a few milliseconds, we are far from nanoseconds avoided thanks to the cache. Anyway, it's now gone ;-)