# ENV — `owned-3d-end-effect`

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` |
| mpmath | 1.3.0 | `python3 -c "import mpmath; print(mpmath.__version__)"` |
| numpy / scipy | 2.2.6 / 1.17.1 | as above |
| FastCap 2 (optional) | source build at `$HOME/tools/src/FastCap2/bin/fastcap`, sha256 `bbc4dd78320ab512…` | the gate's `find_fastcap()` |

**Required tools, and the ENV branch.** `repro.sh` exits 69 with an `ENV:` line when `python3` cannot import mpmath,
numpy and scipy together, because the gate would SKIP. Measured: with `PATH=/usr/bin:/bin` it printed `ENV: …` and
exited 69. FastCap is optional: without it, check [5] records `SKIP:no_fastcap_binary` and does not fail, and the
parsed numbers do not depend on it.

**Runtime and writes.** 44–48 s with FastCap present. It rewrites `benchmarks/bem3d_truth/bem3d_truth_gate_2026_07.json`,
its own output. 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`.