diff --git a/tests/test_lane_helpers.sh b/tests/test_lane_helpers.sh
index 53e5d3c1..4c353785 100755
--- a/tests/test_lane_helpers.sh
+++ b/tests/test_lane_helpers.sh
@@ -63,6 +63,8 @@ done
 [ -f "$SRC_DIR/repos.tsv" ] || { echo "missing: $SRC_DIR/repos.tsv" >&2; exit 1; }
 
 SANDBOX="$(mktemp -d)"
+# Set before the traps below, so `cleanup` never reads an inherited value.
+A11T_ROOT=""
 REAL_HOME="$HOME"
 
 # THE GUARDS AT THE FOOT OF THIS FILE, re-pointed (Amendment 9, act 3
@@ -96,6 +98,9 @@ cleanup() {
   [ -n "${RACE_PARENT:-}" ] && kill "$RACE_PARENT" 2>/dev/null
   [ -n "${RACE_CHILD:-}" ] && kill "$RACE_CHILD" 2>/dev/null
   [ -n "${GD_DUP:-}" ] && kill "$GD_DUP" 2>/dev/null
+  # #180's short checkout root for the clause (c) TAIL case, which is outside
+  # `$SANDBOX` wherever the run root is long.
+  [ -n "${A11T_ROOT:-}" ] && [ -d "$A11T_ROOT" ] && rm -rf -- "$A11T_ROOT"
   [ -n "${SANDBOX:-}" ] && [ -d "$SANDBOX" ] && rm -rf -- "$SANDBOX"
   return 0
 }
@@ -5348,12 +5353,40 @@ has  "…keeping the home and estate the line already carried" "$A11B_LOG" "home
 FAKE_TMUX_WINDOW="a11start:@42" FAKE_TMUX_WINDOW_INDEX=3 FAKE_TMUX_WINDOW_NAME=repoA11b-1 \
   CLAUDE_PROFILE_NAME=team-05a run "$START" repoA11b 1 --no-launch
 is   "lane-start exits 0 on a second start of the same lane" "$rc" 0
-has  "the row's stamp states clause (c)'s two facts for a person, in its TAIL" \
-     "$(grep '^| `repoA11b-1`' "$LANES")" "dir $HOME/projects/repoA11b; window a11start:3 @42"
-has  "…and that tail still says what actually happened, so --no-launch never claims a launch" \
+has  "…and its stamp says what actually happened, so --no-launch never claims a launch" \
      "$(grep '^| `repoA11b-1`' "$LANES")" ", no launch"
 has  "…while its HEAD is Amendment 8(d)'s and is untouched" \
      "$(grep '^| `repoA11b-1`' "$LANES")" "(lane repoA11b-1) — lane-start on Eagle: window renamed, no launch; dir "
+# THE TAIL IS READ ON A CHECKOUT AT A SHORT PATH (opensoft/openRepoTools#180).
+# The stamp is ONE line under ratified decision O1's cap (Amendment 13(a)), and
+# `cut_to_line` takes `dir` and `window` first by design — both are this same
+# act's log sub-fields, asserted in full above — so the tail fits only when the
+# CHECKOUT PATH does. Read on `$HOME/projects/repoA11b`, this case's answer was
+# the run root's length: green under plain pytest's `/tmp`, red under
+# `tests/run.sh`'s per-run root (`… no launch; dir ...`, the path cut whole), at
+# the edge on macOS. The checkout goes in this sandbox's own `$TMPDIR` where
+# that is at most 40 characters, as under plain pytest on Linux, and in `/tmp`
+# where it is not, so `$A11T_DIR` is never over 65 characters and the line never
+# over about 210, inside the 230 the cut keeps wherever the root is. `cleanup`
+# removes it; only a SIGKILLed run under a long root leaves one in `/tmp`.
+# `tests/test_lane_start_row_stamp.py` drives the same stamp at three checkout
+# lengths, the two that are cut included.
+a11t_base="$TMPDIR"
+[ "${#a11t_base}" -le 40 ] || a11t_base=/tmp
+A11T_ROOT="$(mktemp -d "$a11t_base/ort-a11t.XXXXXX" 2>/dev/null || :)"
+A11T_DIR="${A11T_ROOT:-$SANDBOX/a11t-no-short-root}/repoA11t"
+is   "the TAIL case has a checkout of at most 65 characters, wherever the run root is" \
+     "$( [ -n "$A11T_ROOT" ] && [ -d "$A11T_ROOT" ] && [ "${#A11T_DIR}" -le 65 ] && echo yes || echo no )" "yes"
+git init -q -b main "$A11T_DIR"
+git -C "$A11T_DIR" remote add origin "https://github.com/opensoft/repoA11t.git"
+FAKE_TMUX_WINDOW="a11tail:@43" FAKE_TMUX_WINDOW_INDEX=5 FAKE_TMUX_WINDOW_NAME=claude \
+  run "$START" --dir "$A11T_DIR" repoA11t 1 --no-launch
+is   "lane-start exits 0 for a lane whose checkout is at that short path" "$rc" 0
+FAKE_TMUX_WINDOW="a11tail:@43" FAKE_TMUX_WINDOW_INDEX=5 FAKE_TMUX_WINDOW_NAME=repoA11t-1 \
+  run "$START" repoA11t 1 --no-launch
+is   "…and on its second start, which reads the checkout back from the lane's log" "$rc" 0
+has  "the row's stamp states clause (c)'s two facts for a person, in its TAIL" \
+     "$(grep '^| `repoA11t-1`' "$LANES")" "dir $A11T_DIR; window a11tail:5 @43"
 # NO PROFILE IS NO SUB-FIELD, never a guessed one (Amendment 7(i)).
 mkdir -p "$HOME/projects/repoA11c"
 git init -q -b main "$HOME/projects/repoA11c"
diff --git a/tests/test_lane_start_row_stamp.py b/tests/test_lane_start_row_stamp.py
new file mode 100644
index 00000000..ee451e9e
--- /dev/null
+++ b/tests/test_lane_start_row_stamp.py
@@ -0,0 +1,273 @@
+# SPDX-License-Identifier: Apache-2.0
+"""`lane-start`'s row stamp under a long checkout path (opensoft/openRepoTools#180).
+
+THE STAMP'S TAIL IS THE PART A CUT TAKES, AND THAT IS THE DESIGN. Amendment
+11(c) puts the lane's `dir` and `window` in the tail of the stamp a resume
+writes; Amendment 13(a) makes the cell ONE line under ratified decision O1's
+240 characters; and `lane-start` orders that line so `cut_to_line` takes `dir`
+and `window` first, because both are this same act's sub-fields in the lane's
+own log and columns of Amendment 11's listing — a cut loses what a reader can
+look up, never the head `row_stamp_is_unknown` reads.
+
+So the tail's length is the CHECKOUT PATH's length, and #180 was a shell-suite
+case that put its checkout under `$HOME/projects` inside the run root: green
+under plain pytest's short `/tmp`, red under `tests/run.sh`'s per-run root
+(`TMPDIR` about 71 characters, so a `$HOME` about 91). These cases drive a real
+`lane-start` twice, `--no-launch`, in that shape — a `$HOME` at least as long
+as `run.sh`'s — with the checkout at three EXACT lengths, so the answer does not
+depend on where pytest itself was run:
+
+  * a short checkout keeps the whole tail, however long `$HOME` is — which is
+    what `tests/test_lane_helpers.sh`'s clause (c) TAIL case now uses, on a
+    checkout of at most 65 characters;
+  * a checkout whose path still fits loses only the `window` ref;
+  * a longer one loses the path WHOLE, never a truncated path that reads as a
+    real one. That is what #180's case read under `run.sh`'s root:
+    `… window renamed, no launch; dir ...`, its cut landing on the `;` that
+    follows the path, so the path went with it;
+
+and in every one the head is intact, the line is inside the cap, and the
+lane's log carries both facts in full.
+"""
+
+from __future__ import annotations
+
+import os
+import shutil
+import subprocess
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from conftest import REPO, WINDOWS_SKIP, rmtree
+
+pytestmark = [pytest.mark.skipif(shutil.which("bash") is None,
+                                 reason="lane-start is a bash script"),
+              pytest.mark.skipif(shutil.which("git") is None,
+                                 reason="the register is a git repository"),
+              WINDOWS_SKIP]
+
+LANE = "repoZ-1"
+WINDOW = "testsess:0 @1"
+
+#: `tests/run.sh`'s `$HOME` for the shell suite, as #180 measured it: a run
+#: root `TMPDIR` of about 71 characters, the suite's `mktemp -d` beneath it
+#: (`/tmp.XXXXXXXXXX`, 15) and `/home` (5).
+RUN_SH_HOME = 91
+
+SCRUBBED_PREFIXES = ("LANES_", "LANE_START_", "CLAUDE_", "OPENREPOTOOLS_",
+                     "FAKE_", "GIT_", "TMUX")
+SCRUBBED = {"AGENT_PROTOCOL_ROOT", "PROJECTS_ROOT", "XDG_CONFIG_HOME",
+            "XDG_CACHE_HOME"}
+
+#: The lane suite's fake tmux, cut down to one window, `testsess:0 @1`, whose
+#: name is `$FAKE_TMUX_WINDOW_NAME` — `claude` on a first start and the lane
+#: on the second, as a window lane-start renamed would answer.
+FAKE_TMUX = r"""#!/usr/bin/env bash
+case "${1-}" in
+  display-message)
+    shift
+    t=""; f=""
+    while [ $# -gt 0 ]; do
+      case "$1" in
+        -p) shift ;;
+        -t) t="${2-}"; shift 2 ;;
+        *)  f="$1"; shift ;;
+      esac
+    done
+    if [ -n "$t" ]; then
+      case "$t" in
+        testsess:0|testsess:@1|@1) : ;;
+        *) exit 1 ;;
+      esac
+      case "$f" in
+        '#{window_id}')            echo '@1' ;;
+        '#{window_name}')          echo "${FAKE_TMUX_WINDOW_NAME:-claude}" ;;
+        '#{session_name}')         echo 'testsess' ;;
+        '#{pane_current_command}') echo 'claude' ;;
+        *)                         echo ;;
+      esac
+      exit 0
+    fi
+    case "$f" in
+      '#{session_name}:#{window_id}')    echo 'testsess:@1' ;;
+      '#{session_name}:#{window_index}') echo 'testsess:0' ;;
+      '#S:#I')                           echo 'testsess:0' ;;
+      '#{window_id}')                    echo '@1' ;;
+      '#W'|'#{window_name}')             echo "${FAKE_TMUX_WINDOW_NAME:-claude}" ;;
+      *)                                 echo ;;
+    esac ;;
+  rename-window)
+    printf 'rename-window %s\n' "${2-}" >> "$FAKE_TMUX_LOG" ;;
+  *) : ;;
+esac
+"""
+
+#: The workspace repository's first commit: a register with its header and no
+#: rows, and the handoffs directory a row's handoff path points into.
+WORKSPACE_SEED = {
+    "lanes/LANES.md": "\n".join((
+        "# LANES.md -- the sandbox register", "",
+        "| lane | session id | workstation / env / user | started (UTC) | "
+        "objects owned | handoff path | state |",
+        "|---|---|---|---|---|---|---|", "")),
+    "handoffs/README.md": "# handoffs\n",
+}
+
+FAKE_GH = """#!/usr/bin/env bash
+printf 'FAKE gh REFUSED: %s -- this suite reaches no GitHub surface\\n' "$*" >&2
+exit 90
+"""
+
+
+def _write(path: Path, text: str) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(text, encoding="utf-8")
+    path.chmod(0o755)
+
+
+class Sandbox:
+    """One workstation, one register, and a `$HOME` at least `run.sh`'s length."""
+
+    def __init__(self, tmp_path: Path) -> None:
+        pad = max(0, RUN_SH_HOME - len(str(tmp_path / "r" / "home")))
+        self.root = tmp_path / ("r" * (pad + 1))
+        self.home = self.root / "home"
+        assert len(str(self.home)) >= RUN_SH_HOME
+        self.bin = self.root / "bin"
+        fakebin = self.root / "fakebin"
+        origin = self.root / "origin.git"
+        self.wip = self.home / "projects" / "wip"
+        for d in (self.home / "projects", self.root / "tmp", fakebin, self.bin,
+                  self.home / ".claude" / "sessions", self.home / ".agents"):
+            d.mkdir(parents=True, exist_ok=True)
+
+        env = {k: v for k, v in os.environ.items()
+               if k not in SCRUBBED and not k.startswith(SCRUBBED_PREFIXES)}
+        env.update({
+            "HOME": str(self.home),
+            "TMPDIR": str(self.root / "tmp"),
+            "XDG_CONFIG_HOME": str(self.home / ".config"),
+            "XDG_CACHE_HOME": str(self.home / ".cache"),
+            "PATH": f"{fakebin}{os.pathsep}{self.bin}{os.pathsep}{env.get('PATH', '')}",
+            "TMUX": f"{self.root}/fake-tmux-socket,0,0",
+            "AGENT_PROTOCOL_ROOT": str(self.home / ".agents"),
+            "OPENREPOTOOLS_BIN_DIR": str(self.bin),
+            "CLAUDE_CONFIG_DIR": str(self.home / ".claude"),
+            "LANES_WORKSTATION": "Eagle",
+            "LANES_NO_GITHUB": "1",
+            "LANES_INDEX": "off",
+            "FAKE_TMUX_LOG": str(self.root / "tmux.log"),
+            "GIT_AUTHOR_NAME": "lane-start row stamp tests",
+            "GIT_AUTHOR_EMAIL": "test@example.invalid",
+            "GIT_COMMITTER_NAME": "lane-start row stamp tests",
+            "GIT_COMMITTER_EMAIL": "test@example.invalid",
+        })
+        self.env = env
+
+        for name in ("lane-start", "lanes-edit.sh", "repos.tsv"):
+            shutil.copy2(REPO / name, self.bin / name)
+            (self.bin / name).chmod(0o755)
+        _write(fakebin / "tmux", FAKE_TMUX)
+        _write(fakebin / "gh", FAKE_GH)
+        _write(fakebin / "claude", "#!/usr/bin/env bash\nexit 0\n")
+
+        self.git("init", "-q", "--bare", "-b", "main", str(origin))
+        self.git("clone", "-q", str(origin), str(self.wip))
+        for rel, text in WORKSPACE_SEED.items():
+            (self.wip / rel).parent.mkdir(parents=True, exist_ok=True)
+            (self.wip / rel).write_text(text, encoding="utf-8")
+        for step in (("add", "--", *WORKSPACE_SEED), ("commit", "-q", "-m", "seed"),
+                     ("push", "-q", "origin", "main")):
+            self.git("-C", str(self.wip), *step)
+        (self.home / ".agents" / "workspace.yaml").write_text(
+            f"repository: {origin}\npath: {self.wip}\n", encoding="utf-8")
+
+    def git(self, *args: str) -> str:
+        return subprocess.run(["git", *args], env=self.env, check=True,
+                              capture_output=True, text=True).stdout
+
+    def checkout(self, path: Path) -> None:
+        self.git("init", "-q", "-b", "main", str(path))
+        self.git("-C", str(path), "remote", "add", "origin",
+                 "https://github.com/opensoft/repoZ.git")
+
+    def start(self, *args: str, window_name: str) -> subprocess.CompletedProcess:
+        return subprocess.run([str(self.bin / "lane-start"), "repoZ", "1",
+                               "--no-launch", *args],
+                              env=dict(self.env, FAKE_TMUX_WINDOW_NAME=window_name),
+                              capture_output=True, text=True, timeout=120,
+                              check=False)
+
+    def stamp_line(self) -> str:
+        """The `<one line>` of the row's `<STATE> · <UTC> · <one line>` cell."""
+        rows = [r for r in (self.wip / "lanes" / "LANES.md")
+                .read_text(encoding="utf-8").splitlines()
+                if r.startswith(f"| `{LANE}`")]
+        assert len(rows) == 1, rows
+        cell = rows[0].rstrip().rstrip("|").rstrip().rsplit(" | ", 1)[1]
+        state, _utc, line = cell.split(" · ", 2)
+        assert state == "LIVE", cell
+        return line
+
+    def last_log_line(self) -> str:
+        return (self.wip / "lanes" / "log" / f"{LANE}.md").read_text(
+            encoding="utf-8").splitlines()[-1]
+
+
+@pytest.fixture
+def short_root():
+    """A short, FIXED-length directory outside the run root: `/tmp/` and
+    `mkdtemp`'s name, whatever `TMPDIR` or pytest's basetemp say."""
+    root = Path(tempfile.mkdtemp(prefix="ort-tail.", dir="/tmp"))
+    try:
+        yield root
+    finally:
+        rmtree(root)
+
+
+def _checkout_of_length(root: Path, length: int | None) -> Path:
+    """`<root>/repoZ`, padded between the two to exactly `length` characters."""
+    if length is None:
+        return root / "repoZ"
+    pad = length - len(str(root)) - len("/repoZ") - 1
+    assert pad > 0, (root, length)
+    path = root / ("p" * pad) / "repoZ"
+    assert len(str(path)) == length
+    return path
+
+
+@pytest.mark.parametrize("length, keeps", [
+    pytest.param(None, "dir and window", id="short-fixed-checkout"),
+    pytest.param(100, "dir", id="window-cut-dir-kept"),
+    pytest.param(160, "nothing", id="path-dropped-whole-as-in-180"),
+])
+def test_the_stamp_tail_is_cut_by_the_checkout_path_and_never_the_head(
+        tmp_path, short_root, length, keeps):
+    box = Sandbox(tmp_path)
+    lane_dir = _checkout_of_length(short_root, length)
+    box.checkout(lane_dir)
+
+    first = box.start("--dir", str(lane_dir), window_name="claude")
+    assert first.returncode == 0, first.stderr
+    # THE SECOND START STAMPS (Amendment 6(c)), and it finds the checkout in
+    # the lane's own log, exactly as the shell suite's case does.
+    second = box.start(window_name=LANE)
+    assert second.returncode == 0, second.stderr
+    line = box.stamp_line()
+
+    assert len(line) <= 240, line
+    assert (f"(lane {LANE}) — lane-start on Eagle: window renamed, "
+            f"no launch; dir ") in line, line
+    if keeps == "dir and window":
+        assert line.endswith(f"; dir {lane_dir}; window {WINDOW}"), line
+    elif keeps == "dir":
+        assert f"; dir {lane_dir};" in line and line.endswith(" ..."), line
+        assert WINDOW not in line, line
+    else:
+        assert line.endswith("no launch; dir ..."), line
+        assert str(short_root) not in line, line
+
+    # NOTHING IS LOST: what the cut took is this act's own log line.
+    assert f"; dir {lane_dir}; window {WINDOW}; " in box.last_log_line()