requests.Session(trust_env=False) prevents responses from intercepting HTTP requests

[ikus060]

When creating a requests.Session with trust_env=False, the responses library fails to intercept the HTTP requests as expected. The request appears to bypass the mock entirely and attempts a real network call instead.
This behavior is not documented anywhere in the responses README or official documentation. It is unclear whether this is:

• A known limitation
• An intended behavior
• A bug

Kindly requesting either a fix or at minimum clear documentation of this interaction.

[vismaytiwari]

I wanted to take a crack at fixing this, but I can't get it to reproduce — am I missing something?

On responses 0.26.2 / requests 2.34.2 this gets mocked correctly for me:

@responses.activate
def test():
    responses.add(responses.GET, "https://example.com/api", json={"ok": True})
    s = requests.Session()
    s.trust_env = False
    assert s.get("https://example.com/api").json() == {"ok": True}  # passes

I also tried it with HTTP(S)_PROXY/NO_PROXY set in the env and with the session created before responses starts — all intercept fine. responses patches HTTPAdapter.send at the class level, so it looks independent of trust_env.

Could you share a minimal repro (responses/requests versions + the exact Session setup)? Happy to dig in once I can see it fail.