Exception in memory_zone does not clear vocab

[ghinch]

When using the nlp.memory_zone(), if an exception occurs inside the memory zone and you then try and use the nlp object to process another doc, it retains the vocab from the previous use.

How to reproduce the behaviour

import spacy

def spacy_proc(nlp, text, should_raise=False):
    with nlp.memory_zone():
        doc = nlp(text)
        for token in doc:
            print(token.text, token.pos_, token.dep_)

        if should_raise:
            raise Exception("This is a test exception to check memory zone handling.")

        return doc

def main():
    nlp = spacy.load("en_core_web_md")
    try:
        spacy_proc(nlp, "This is a test sentence to check memory zones in spaCy.", should_raise=True)
    except Exception:
        pass  # Handle the exception gracefully

    spacy_proc(nlp, "Some more text to process after the exception.")
    # raises AssertionError on "spacy/vocab.pyx", line 199, in spacy.vocab.Vocab.get

You can work around this by using a try/except inside the memory zone, and raising the caught exception outside of it, like this:

import spacy

def spacy_proc(nlp, text, should_raise=False):
    err = None
    with nlp.memory_zone():
        try:
          doc = nlp(text)
          for token in doc:
              print(token.text, token.pos_, token.dep_)

          if should_raise: 
              raise Exception("This is a test exception to check memory zone handling.")

          return doc
        except Exception as e:
             err = e
    raise err  # raise _after_ the memory zone closes

def main():
    nlp = spacy.load("en_core_web_md")
    try:
        spacy_proc(nlp, "This is a test sentence to check memory zones in spaCy.", should_raise=Tr  ue)
    except Exception:
        pass  # Handle the exception gracefully

    spacy_proc(nlp, "Some more text to process after the exception.") # succeeds

I'm not sure if this is the intended implementation, but it feels like a sharp edge to me and should be documented. Or the memory zone should ensure it handles exceptions and closes down correctly before raising them.

Your Environment

Info about spaCy

• spaCy version: 3.8.11
• Platform: macOS-26.1-arm64-arm-64bit-Mach-O (also seeing this on AWS Graviton, ARM environment)
• Python version: 3.13.3
• Pipelines: en_core_web_md (3.8.0)