Re-arm Elixir test gate: root-cause `mix test --no-start` full-app-boot failure (burble#35 item 2)

[hyperpolymath]

Sub-issue of #35 (item 2). Tracks the blocked work: root-cause and fix the Test (OTP 27 / Elixir 1.17) failure so the gate can be re-armed. Do not remove continue-on-error until the suite is green on main.

Root-cause lead (evidence gathered 2026-05-17)

The failure is almost certainly a full-app-boot failure under mix test --no-start, not individual assertions:

1. Justfile:245 → cd server && mix test --no-start.
2. server/test/test_helper.exs → Application.ensure_all_started(:burble) (manually boots the whole app because --no-start suppressed the automatic start).
3. server/lib/burble/application.ex start/2 has no test-env guard — it unconditionally boots the full production supervision tree: Burble.Store (VeriSimDB @ http://localhost:8081), Burble.Transport.RTSP (TCP 8554), Burble.Bolt.Listener (UDP 7373), Burble.LLM.Supervisor (QUIC 8503 via :quicer/msquic NIF), Burble.Media.Engine, Zig coprocessor NIF (server/priv/libburble_coprocessor.so).
4. config/test.exs only sets Endpoint server: false; it does not disable Burble.Store or the network/NIF children.
5. In CI none of these externals exist: VeriSimDB is not running on :8081, the Zig FFI .so may be absent (the "Build Zig FFI" step is itself continue-on-error, so a failed build silently yields no .so), and the quicer NIF/msquic may be unavailable.

⇒ The first hard-crashing child collapses Burble.Supervisor; ensure_all_started(:burble) returns {:error, …}; every test fails at startup — exactly the predicted mode.

(Local repro on this machine is non-authoritative: toolchain is Elixir 1.18.4/OTP 25 vs CI 1.17/OTP 27, and a separate Guardian.Plug.Pipeline compile error blocks local boot. Confirming which child crashes first still needs the blocking prerequisite below.)

Blocking prerequisite (unchanged from #35)

ONE of: widen cloud-sandbox allowlist to repo.hex.pm + builds.hex.pm; or an actions:read token / Actions-logs MCP tool; or paste the failing ** ( / N) test … failed block.

Remediation directions (decide once root cause confirmed)

• A. Test-env start path: filter Burble.Application children via Application.compile_env(:burble, :start_children) so test boots only the minimal set (PubSub/registries/store-stub), excluding network listeners + external-dep children.
• B. Drop --no-start; disable heavy children via config/test.exs flags the supervisor honours.
• C. Build the Zig coprocessor .so before tests and re-arm the FFI gate (the FFI continue-on-error is part of the failure surface).

Acceptance criteria (from #35)

• just test-server passes on main for OTP 27 / Elixir 1.17
• continue-on-error: true removed from "Run server tests"; a planted failing test turns CI red
• "GATE DEACTIVATED" comment removed with it
• Consider gating dialyzer (it needs: test) and re-arming the "Build Zig FFI" gate

Refs #35

[hyperpolymath]

Root cause found — the static lead in the issue body was WRONG

Pulled the actual Test (OTP 27 / Elixir 1.17) run log (CI-logs unblock path). The failure is not app-boot under mix test --no-start:

##[group]Run just test-server
error: Unknown start of token:
   |
11 | import? "contractile.just"
   |       ^
##[error]Process completed with exit code 1.

just test-server aborts at the Justfile's import? (optional import, just ≥ 1.19.0). The workflow's unversioned tool: just resolves via taiki-e/install-action@v2.9.4's bundled manifest → just 1.14.0, which predates import?. mix test --no-start never ran — the suite was never actually executing, which is why it appeared "red for a pre-existing reason." The Application.ensure_all_started(:burble) / NIF / app-boot hypothesis is moot until just runs at all.

Fix: PR #40 — pin tool: just@1.34.0. Does not remove continue-on-error (per #35/#39, gate is re-armed only after the suite is confirmed green on main with just actually running). Once #40 merges, the genuine mix test --no-start result becomes visible and this issue proceeds on evidence: green → re-arm the gate; or a real, evidence-based test fix.

[hyperpolymath]

Static root-cause confirmation (CI-independent; pending real-log verification)

With the just@1.34.0 pin (PR #40) mix test --no-start will now actually
execute for the first time. Static analysis pins the exact failure it will
hit — and it is precisely the original #39 lead (the #40 fix addressed why
the suite never ran, not whether it passes once it does):

Failure chain, line-pinned:

1. Justfile:245 → cd server && mix test --no-start
2. server/test/test_helper.exs:3 → Application.ensure_all_started(:burble)
   — return value is ignored (no {:ok, _} / {:error, _} match)
3. server/lib/burble/application.ex start/2 — no test-env guard;
   Burble.Store is the first child; strategy: :one_for_one
4. server/lib/burble/store.ex:224-259 init/1:
   • await_verisimdb(client, @health_check_max_attempts=5, 1_000)
   • VeriSimDB is not running on :8081 in CI (config/test.exs
     points Burble.Store at http://localhost:8081, auth: :none)
   • 5 attempts with backoff → {:error, :unreachable} →
     {:stop, :verisimdb_unreachable} (store.ex:259)
5. First permanent child {:stop, …} during Supervisor.start_link →
   whole supervisor start aborts → ensure_all_started/1 returns
   {:error, …} → app, Store, registries, BurbleWeb.Endpoint all down
6. test_helper.exs ignores that error → ExUnit runs with no app
   started → every app-dependent test fails. Suite RED (and ~30s
   slower from the health-check backoff).

config/test.exs only sets Endpoint server: false; it does not
disable Burble.Store or the network/NIF children — confirming the gap.

⇒ The continue-on-error: true on "Run server tests" must stay until
this is fixed; re-arming now would redden main on the first real run.

Per-#40 discipline: a confident static lead was wrong about the
primary cause there, so the remediation PR still waits on the actual CI
log to confirm which child stops first. Watcher is on the latest main
Elixir CI run (currently queued on GitHub's runner backlog).

Remediation recommendation (decide once CI confirms): direction A
is cleanest — gate Burble.Application children via
Application.compile_env(:burble, :start_children), with config/test.exs
selecting a minimal set (PubSub + registries + dynamic supervisors + ETS
stores), excluding Burble.Store/BackupScheduler/Media.Engine/RTSP/
LLM.Supervisor/Bolt.Listener/Endpoint, plus a test Store stub for
suites that exercise the data layer. Direction C (build the Zig .so

• re-arm the FFI gate) is complementary, not a substitute — Burble.Store
  is the hard blocker regardless of the NIF.

Refs #35

[hyperpolymath]

Cross-ref: the generalised lesson from this root cause is now institutionalised estate-wide — see hyperpolymath/standards#95 (Tooling Version Integrity rollout) and the policy in hyperpolymath/standards#94. This issue (final Elixir gate re-arm) remains tracked there under the burble#35 item-2 handoff; it stays blocked on the queued CI signal, watcher live. No change to the re-arm discipline: confirm green before removing continue-on-error.

[hyperpolymath]

Scheduled gate-rearm agent: RED — gate left disarmed (correct)

Evidence summary

The just@1.34.0 fix from PR #40 (commit 5bd0ccab) works: just test-server now parses the Justfile's import? directive without error, and mix test --no-start genuinely executes for the first time. The Elixir suite has real failures.

Authoritative run: 25979890037 (job 76366588721, "Test (OTP 27 / Elixir 1.17)"), commit 44a972920ae8315bec6260d6d42da9db85024827 (latest main, 2026-05-18).

Confirmation that just and mix test now run

# From "Run server tests" step annotations — run 25979890037

WARN  Install just: just@1.34.0 for 'linux' is not supported; fallback to cargo-binstall
      (just 1.34.0 installed via cargo-binstall — Justfile import? parses without error)

WARN  Run server tests: 0..(2 <<< 14) - 1 inside guards requires an explicit step,
      please write 0..(2 <<< 14) - 1//1 or 0..(2 <<< 14) - 1//-1 instead
WARN  Run server tests: x..y inside match is deprecated, you must always match on the step

ERROR Run server tests: Process completed with exit code 1.

The two Elixir range-syntax warnings are emitted by OTP 27 / Elixir 1.17 during mix test's compilation phase — proof that mix test --no-start executed. The step then exits 1 (test failures).

Failing tests (10 annotations, run 25979304208, commit 5bd0ccab — same Elixir code)

ERROR  Topology.Transition — transition to :monarchic (unexpected result)
ERROR  Topology.Transition — transition to :oligarchic (unexpected result)
ERROR  Topology.Transition — transition to :distributed (unexpected result)
ERROR  Topology.Transition — transition to :serverless (unexpected result)
ERROR  Burble.Bridges.DiscordCryptoTest — xchacha20_poly1305 cipher test
ERROR  Burble.Bridges.DiscordCryptoTest — startup cipher probe (GenServer.start_link)
ERROR  Burble.Bridges.DiscordCryptoTest — cipher behaviour
ERROR  Burble.Safety.ProvenBridge — test
ERROR  Network.Chaos — test
(+ 1 more)

Root cause diagnosis

test_helper.exs silently drops app-boot errors:

# server/test/test_helper.exs
ExUnit.start()
Application.ensure_all_started(:burble)   # ← no error check

Under mix test --no-start, Mix doesn't start the application. ensure_all_started/1 attempts to start it but returns {:error, {app, reason}} if boot fails (e.g., quicer/msquic NIF not available). The return value is discarded — the app silently never starts.

Topology.Transition tests fail because Room.get_state/1 needs a running Repo:

# server/lib/burble/topology/transition.ex
def transition_room(room_id, new_mode) do
  case Room.get_state(room_id) do   # ← requires Ecto Repo to be started
    {:ok, state} -> ...
    error -> error                  # returns {error, reason} — not {:error, :fork_not_implemented}
  end
end

The distributed/serverless tests assert {:error, :fork_not_implemented} but Room.get_state returns a different error (Repo not running), so the assertion fails. The monarchic/oligarchic tests accept :ok or {:error, :not_found} — but Room.get_state crashes/returns an unexpected tuple when Repo is down.

Discord startup probe (discord_crypto_test.exs) is app-boot dependent:

test "bridge starts successfully when :xchacha20_poly1305 is available" do
  result = GenServer.start_link(Burble.Bridges.Discord, opts)
  assert {:ok, pid} = result   # ← fails if Discord.init/1 needs app infrastructure
end

Burble.Bridges.Discord.init/1 likely calls into Registry or other supervised processes that don't exist when the app didn't boot.

Verdict

The original "app-boot under --no-start / NIF" hypothesis from #35/#39 is now testable and confirmed as the root cause of test failures. mix test --no-start DOES run, but the test suite was written assuming Application.ensure_all_started(:burble) succeeds. The next step for green is one (or more) of:

1. Fix test_helper.exs to check the return value and explicitly start or mock required subsystems when the app fails to boot.
2. Investigate why ensure_all_started(:burble) fails — most likely quicer/msquic NIF can't load. The ensure-msquic-version.sh/ensure-quicer-prereqs.sh scripts pass (evidenced by mix test reaching compilation), so the build completes; the NIF load on first Application.start may be the sticking point.
3. Tag process-dependent tests with @moduletag :requires_app and conditionally skip them in CI until the app-boot path is fixed.

Gate remains disarmed per #35/#39 acceptance criteria (re-arm only on confirmed green). This evidence confirms the suite now genuinely runs — failures are real and fixable.

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Scheduled agent run 2026-05-18. Runs examined: 25979890037 (latest main, 44a97292) and 25979304208 (PR #40 merge, 5bd0ccab). No workflow files modified.

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