fix(attach): hints print the row's attach_command (Issue #72, comments 926/930, U1)

create's closing hint, the delegate-job wrapper's dispatch hint and stop's
stuck-TUI message printed the pre-#71 forms (`herdr session attach <name>`,
`HERDR_SESSION_NAME=... herdr agent attach <name>`), which miss an agent whose
name is over 32 characters or has upper case. They now print the session row's
attach_command, or lib_py.agents.sanitize.attach_command(server, name) when
there is no row (lib.sh session_attach_command). deploy/INSTALL.md and
install_mam.sh show the `herdr --session <server> agent attach <herdr name>`
form.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.agents/skills/lib.sh

@@ -1671,6 +1671,22 @@ print(resolved)
 "
 }
 
+# session_attach_command <session_name> [server]
+#
+# Issue #72: the attach hint a script prints - the session row's
+# attach_command, else the one lib_py.agents.sanitize.attach_command builds for
+# <server> (default: `default`).
+session_attach_command() {
+  MAM_STATE_JSON="$(load_state_json)" SESSION_NAME="$1" ATTACH_SERVER="${2:-default}" python3 -c "
+import os, json
+from lib_py.agents.sanitize import attach_command
+name = os.environ['SESSION_NAME']
+d = json.loads(os.environ.get('MAM_STATE_JSON') or '{}')
+row = next((s for s in d.get('herdr_sessions', []) if s.get('name') == name), {})
+print(row.get('attach_command') or attach_command(os.environ['ATTACH_SERVER'], name))
+"
+}
+
 # resolve_herdr_session <session_name> [workspace]
 #
 # returns the isolated herdr *session* name (socket/daemon) to use for this MAM session row,

.agents/skills/multi-agent-mux-create/scripts/create_session.sh

@@ -767,6 +767,6 @@ fi
 trap - EXIT
 echo "agent-sessions.yaml updated"
 echo
-echo "Attach:  herdr session attach $SESSION_NAME"
+echo "Attach:  $(session_attach_command "$SESSION_NAME" "${HERDR_SESSION_NAME:-default}")"
 echo "Delete:  use multi-agent-mux-stop skill"
 echo "Resume:  use multi-agent-mux-resume skill (after first message creates a session id)"

.agents/skills/multi-agent-mux-delegate-job/multi-agent-mux-delegate-job

@@ -1018,7 +1018,7 @@ inject_agent() {
     return 1
   fi
 
-  echo "작업이 세션 '$sess'에 전송되었습니다. (연결하려면: HERDR_SESSION_NAME=$HERDR_SESSION_NAME herdr agent attach $sess — lib.sh를 source한 셸에서 실행)"
+  echo "작업이 세션 '$sess'에 전송되었습니다. (연결하려면: $(session_attach_command "$sess" "${HERDR_SESSION_NAME:-default}"))"
   trap - EXIT
   return 0
 }

.agents/skills/multi-agent-mux-stop/scripts/stop_session.sh

@@ -332,7 +332,7 @@ if [ "$PURGE" = "1" ] && [ "$HERDR_ALIVE" = "1" ]; then
   if herdr has-session -t "$SESSION_NAME" 2>/dev/null; then
     echo "ERROR: session '$SESSION_NAME' is still alive after the kill chain." >&2
     echo "  Refusing registry removal — records preserved (no state was modified)." >&2
-    echo "  Diagnose the stuck TUI (herdr session attach '$SESSION_NAME'), then re-run" >&2
+    echo "  Diagnose the stuck TUI ($(session_attach_command "$SESSION_NAME" "${HERDR_SESSION_NAME:-default}")), then re-run" >&2
     echo "  stop_session.sh --purge-conversation --yes (retry is safe/idempotent)." >&2
     delegate_publish_event "$DELEGATE_JOB_ID" cancelled "purge aborted: session still alive; no state was modified" "$DELEGATE_JOB_TOKEN" "$DELEGATE_JOB_ATTEMPT"
     exit 4

deploy/INSTALL.md

@@ -60,7 +60,7 @@ $ bash .agents/skills/multi-agent-mux-create/scripts/create_session.sh \
 ### 2) 세션 접속 (Attach)
 백그라운드에서 구동된 에이전트 TUI 화면에 들어갑니다.
 ```bash
-$ herdr session attach my-project-dev-claude
+$ herdr --session multi-agent-mux agent attach my-project-dev-claude
 ```
 *   **화면 탈출**: 대화 중 세션을 유지한 채 터미널로 돌아오려면 `Ctrl + B`를 누른 뒤 `D` 키를 차례로 입력합니다.
 

deploy/install_mam.sh

@@ -327,7 +327,7 @@ cat <<EOF
          --herdr-server multi-agent-mux
 
   2. Attach to the running session:
-     $ HERDR_SERVER_NAME=multi-agent-mux herdr agent attach <session_name>
+     $ herdr --session multi-agent-mux agent attach <herdr name>
 
   3. Gracefully stop the session:
      $ bash .agents/skills/multi-agent-mux-stop/scripts/stop_session.sh \\

tests/test_issue72_attach_hints.py

@@ -0,0 +1,184 @@
+"""Issue #72: the attach hints create, stop and the delegate-job wrapper print
+are the session row's attach_command (Issue #71); with no row, the one
+lib_py.agents.sanitize.attach_command builds for the server the script used.
+"""
+import json
+import os
+import re
+import subprocess
+import sys
+import time
+from pathlib import Path
+
+import pytest
+import yaml
+
+REPO = Path(__file__).resolve().parent.parent
+SKILLS = REPO / ".agents" / "skills"
+sys.path.insert(0, str(SKILLS))
+
+from lib_py.agents.sanitize import attach_command, sanitize_herdr_agent_name  # noqa: E402
+
+LONG = "lab-issue72-a-very-long-branch-name-creator-claude"   # > 32 characters
+UPPER = "Lab-Upper72-creator-claude"
+
+
+def _set_mock(mock_herdr, **kw):
+    state = json.loads(Path(mock_herdr).read_text())
+    state.update(kw)
+    Path(mock_herdr).write_text(json.dumps(state))
+
+
+def _rows(sandbox):
+    return yaml.safe_load((sandbox / ".mam" / "agent-sessions.yaml").read_text())["herdr_sessions"]
+
+
+def _seed(sandbox, rows):
+    lib = sandbox / ".agents" / "skills" / "lib.sh"
+    mutation = "d['herdr_sessions'] = " + repr(rows) + "\n"
+    res = subprocess.run(["bash", "-c", 'source "$1" && atomic_dump_yaml "$AGENT_SESSIONS_YAML"', "_", str(lib)],
+                         input=mutation, capture_output=True, text=True)
+    assert res.returncode == 0, res.stderr
+
+
+def _row(name, server, cwd, pid=1):
+    return {"name": name, "status": "running", "role": "creator", "agent": "claude",
+            "herdr_session": server, "herdr_server": server, "attach_command": attach_command(server, name),
+            "pane": {"index": 0, "pid": pid, "cmd": "claude", "cwd": str(cwd)}}
+
+
+def _seeded_attach(sandbox, name, server):
+    (row,) = [r for r in _rows(sandbox) if r["name"] == name]
+    assert row["attach_command"] == attach_command(server, name)
+    return row["attach_command"]
+
+
+def _agent(cwd, pane, pid=9999):
+    return {"agent": "claude", "status": "running", "agent_status": "idle", "cwd": str(cwd), "workspace_id": "w1",
+            "pid": pid, "pane_id": pane, "command": "claude", "buffer": "Ready"}
+
+
+# --- create ---------------------------------------------------------------------
+
+@pytest.mark.parametrize("name", [LONG, UPPER])
+def test_create_prints_the_rows_attach_command(mam_sandbox, mock_herdr, mock_agents, name):
+    assert sanitize_herdr_agent_name(name) != name, "the herdr name differs from the session name"
+    _set_mock(mock_herdr, strict_agent_names=True)
+    script = mam_sandbox / ".agents" / "skills" / "multi-agent-mux-create" / "scripts" / "create_session.sh"
+    res = subprocess.run(["bash", str(script), "--workspace", str(mam_sandbox), "--agent", "claude",
+                          "--role", "creator", "--session", name, "--herdr-session", "mam-iso72", "--no-onboard"],
+                         capture_output=True, text=True, cwd=str(mam_sandbox), timeout=300,
+                         env=dict(os.environ, MAM_NO_SUBSCRIBER_DAEMON="1"))
+    assert res.returncode == 0, res.stdout + res.stderr
+    (row,) = [r for r in _rows(mam_sandbox) if r["name"] == name]
+    hints = [l for l in res.stdout.splitlines() if l.startswith("Attach:")]
+    assert hints == ["Attach:  " + row["attach_command"]], res.stdout
+    assert row["attach_command"] == attach_command("mam-iso72", name)
+
+
+# --- stop: the stuck-TUI message ------------------------------------------------
+
+def _undying_herdr(mam_sandbox):
+    """The mock herdr behind a wrapper that ignores every way to close a pane,
+    so the session survives stop's kill chain."""
+    bin_dir = mam_sandbox / "bin"
+    (bin_dir / "herdr").rename(bin_dir / "herdr-mock72")
+    (bin_dir / "herdr").write_text(
+        '#!/usr/bin/env bash\nfor a in "$@"; do case "$a" in kill-session|close) exit 0 ;; esac; done\n'
+        'exec "%s" "$@"\n' % (bin_dir / "herdr-mock72"))
+    (bin_dir / "herdr").chmod(0o755)
+
+
+@pytest.mark.parametrize("name", [LONG, UPPER])
+def test_stop_stuck_tui_message_shows_the_rows_attach_command(mam_sandbox, mock_herdr, mock_agents, name):
+    # The SIGKILL fallback kills the pane pid: make it a child of this test.
+    pane = subprocess.Popen(["sleep", "300"])
+    try:
+        # The row's server is not the one passed on the command line: the row wins.
+        _seed(mam_sandbox, [_row(name, "mam-row72", mam_sandbox, pid=pane.pid)])
+        want = _seeded_attach(mam_sandbox, name, "mam-row72")
+        _set_mock(mock_herdr, strict_agent_names=True,
+                  agents={sanitize_herdr_agent_name(name): _agent(mam_sandbox, "w1:p72", pid=pane.pid)})
+        _undying_herdr(mam_sandbox)
+        script = mam_sandbox / ".agents" / "skills" / "multi-agent-mux-stop" / "scripts" / "stop_session.sh"
+        res = subprocess.run(["bash", str(script), "--session", name, "--agent", "claude",
+                              "--herdr-session", "mam-arg72", "--purge-conversation", "--yes"],
+                             capture_output=True, text=True, cwd=str(mam_sandbox), timeout=300,
+                             env=dict(os.environ, SKS_IDLE_TIMEOUT_MS="500"))
+    finally:
+        pane.kill()
+        pane.wait()
+    assert res.returncode == 4, res.stdout + res.stderr
+    hints = [l for l in res.stderr.splitlines() if "Diagnose the stuck TUI" in l]
+    assert hints == ["  Diagnose the stuck TUI (%s), then re-run" % want], res.stderr
+
+
+# --- delegate-job wrapper ---------------------------------------------------------
+
+def _delegate(mam_sandbox, mock_herdr, name):
+    """Submit a job to herdr:<name>, acknowledge it as the agent would, and
+    return (stdout, the herdr server the wrapper prompted)."""
+    reg_dir = mam_sandbox / ".mam" / "jobs"
+    reg_dir.mkdir(parents=True, exist_ok=True)
+    wrapper = mam_sandbox / ".agents" / "skills" / "multi-agent-mux-delegate-job" / "multi-agent-mux-delegate-job"
+    publish = mam_sandbox / ".agents" / "skills" / "multi-agent-mux-delegate-job" / "scripts" / "publish_event.py"
+    env = dict(os.environ, DELEGATE_JOB_PYTHON=sys.executable, MQTT_HOST="127.0.0.1", MQTT_PORT="65534",
+               SKS_IDLE_TIMEOUT_MS="500", MAM_INJECT_ACK_GRACE_S="20")
+    proc = subprocess.Popen(["bash", str(wrapper), "submit", "--agent", "claude-code",
+                             "--agent-session", "herdr:" + name, "--prompt", "issue 72 attach hint",
+                             "--registry-dir", str(reg_dir), "--workdir", str(mam_sandbox),
+                             "--timeout", "6", "--idle-timeout", "2"],
+                            cwd=str(mam_sandbox), env=env, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
+    try:
+        tok, jid = "", ""
+        deadline = time.time() + 60
+        while time.time() < deadline and not tok:
+            for f in reg_dir.glob("*.json"):
+                try:
+                    tok, jid = json.loads(f.read_text()).get("dispatch_token") or "", f.stem
+                except ValueError:
+                    pass
+            time.sleep(0.2)
+        assert tok, "the job was not dispatched"
+        ack = subprocess.run([sys.executable, str(publish), "--registry-dir", str(reg_dir), "--job", jid,
+                              "--event", "started", "--expect-dispatch-token", tok, "--attempt-id", "1"],
+                             capture_output=True, text=True, cwd=str(mam_sandbox), env=env, timeout=60)
+        # publish_event records `started` locally before its (here unreachable) broker publish
+        assert '"started"' in (reg_dir / (jid + ".events.log")).read_text(), ack.stderr
+        stdout, stderr = proc.communicate(timeout=180)
+    finally:
+        if proc.poll() is None:
+            proc.kill()
+            proc.communicate()
+    calls = json.loads(Path(mock_herdr).read_text())["calls"]
+    prompts = [c for c in calls if "agent" in c[:3] and "prompt" in c[:4]]
+    assert prompts, (calls, stdout, stderr)
+    servers = {c[1] if c[0] == "--session" else "default" for c in prompts}
+    assert len(servers) == 1, prompts
+    return stdout + stderr, servers.pop()
+
+
+def _delegate_hint(out):
+    hints = [m.group(1) for m in (re.search(r"\(연결하려면: (.*)\)$", l) for l in out.splitlines()) if m]
+    assert len(hints) == 1, out
+    return hints[0]
+
+
+@pytest.mark.parametrize("name", [LONG, UPPER])
+def test_delegate_prints_the_rows_attach_command(mam_sandbox, mock_herdr, mock_agents, name):
+    _seed(mam_sandbox, [_row(name, "mam-row72", mam_sandbox)])
+    want = _seeded_attach(mam_sandbox, name, "mam-row72")
+    _set_mock(mock_herdr, strict_agent_names=True,
+              agents={sanitize_herdr_agent_name(name): _agent(mam_sandbox, "w1:p72")})
+    out, server = _delegate(mam_sandbox, mock_herdr, name)
+    assert server == "mam-row72"
+    assert _delegate_hint(out) == want
+
+
+@pytest.mark.parametrize("name", [LONG, UPPER])
+def test_delegate_without_a_row_builds_it_for_the_server_it_used(mam_sandbox, mock_herdr, mock_agents, name):
+    assert not any(r["name"] == name for r in _rows(mam_sandbox))
+    _set_mock(mock_herdr, strict_agent_names=True,
+              agents={sanitize_herdr_agent_name(name): _agent(mam_sandbox, "w1:p72")})
+    out, server = _delegate(mam_sandbox, mock_herdr, name)
+    assert _delegate_hint(out) == attach_command(server, name)