# ENV — `extraction-to-circuit-boundary`

Measured 2026-09-17 on the machine that built this packet, under the estate proof environment
(`env -u LC_ALL PATH="/opt/homebrew/opt/python@3.11/libexec/bin:$HOME/.local/bin:$HOME/.elan/bin:$HOME/.cargo/bin:/opt/homebrew/bin:$PATH"`, stdin `/dev/null`),
in a tree holding exactly the committed HEAD (built by `repro/verify_packets.py`, never the lane's working tree).

| tool | version | probe |
|---|---|---|
| macOS | 26.6, arm64 | `sw_vers`, `uname -m` |
| python3 | 3.11.14 (`/opt/homebrew/opt/python@3.11/libexec/bin/python3`) | `python3 --version` |
| scikit-rf | 1.10.0 | `python3 -c "import skrf; print(skrf.__version__)"` |
| numpy / scipy | 2.2.6 / 1.17.1 | `python3 -c "import numpy, scipy; print(numpy.__version__, scipy.__version__)"` |

**Required tool, and the ENV branch.** `repro.sh` exits 69 with an `ENV:` line when `python3` cannot import `skrf`,
because the witness would SKIP (its rc 2). Measured: with `PATH=/usr/bin:/bin` (the system interpreter) the script
printed `ENV: …` and exited 69.

**Runtime and writes.** 11.7–12.8 s. It rewrites `benchmarks/export/passivity_enforce_2026_07_01.json`, its own
output, which is not an input. In the lane's working tree that file carries another session's uncommitted edit, so
never run this packet there.

**Lean.** This witness runs no Lean. If a later packet needs it: the Lean 4 toolchain is `~/.elan/bin/lean` (4.34.0 here),
and `/opt/homebrew/bin/lean` is a different program (`lean 1.0.223`). Never trust whichever `lean` comes first on `PATH`.