diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b84e3f3..321b09b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -61,6 +61,8 @@ jobs:
         run: pip3 install --quiet pyyaml
       - name: Check local and GitHub runners cover the same work
         run: bash testing/check-ci-parity.sh
+      - name: Check test log matchers against the strings src/ emits
+        run: python3 testing/check-log-strings.py
 
   fmt:
     name: Format check
diff --git a/testing/check-log-strings.py b/testing/check-log-strings.py
new file mode 100755
index 0000000..7a597f9
--- /dev/null
+++ b/testing/check-log-strings.py
@@ -0,0 +1,252 @@
+#!/usr/bin/env python3
+"""Verify that every daemon log string a test matches on still exists in src/.
+
+A test that greps the daemon's log for a message the daemon no longer emits
+does not fail — it quietly stops observing anything, and an assertion built on
+it (especially one expecting a count of zero) passes for the wrong reason.
+That class has produced several findings, so it is checked mechanically here
+rather than re-discovered by reading.
+
+The check extracts the string literals that test code matches against daemon
+log lines, reduces each to its longest literal run (patterns carry regex
+syntax), and requires that run to appear somewhere under src/. Anything that
+legitimately does not originate in src/ — runtime panic text, tracing's own
+level tokens — must be named in ALLOWED with a reason, so the exceptions are
+reviewable instead of invisible.
+
+Usage: testing/check-log-strings.py [--verbose]
+Exit:  0 all matched strings are live, 1 otherwise.
+"""
+
+from __future__ import annotations
+
+import re
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parent.parent
+SRC = REPO / "src"
+TESTING = REPO / "testing"
+
+# Strings matched against log text that do not come from src/, each with the
+# reason it is legitimately absent. Anything here is exempt from the src/
+# existence requirement — keep the list short and the reasons specific.
+ALLOWED = {
+    "panicked": "emitted by the Rust runtime's panic hook, not by our code",
+    "PANIC": "panic-adjacent marker matched defensively alongside 'panicked'",
+    "ERROR": "tracing's own level token, produced by the subscriber's formatter",
+    " ERROR ": "tracing's own level token, produced by the subscriber's formatter",
+    " WARN ": "tracing's own level token, produced by the subscriber's formatter",
+    "Bootstrapped 100%": (
+        "read from the tor-daemon container's log, not the fips daemon's — "
+        "Tor's own bootstrap progress line"
+    ),
+    "panicked at": "the Rust runtime's panic hook writes this, not our code",
+    "RUST_BACKTRACE": "the runtime's backtrace hint, printed alongside a panic",
+    "fatal runtime error": "emitted by the Rust runtime on an abort",
+}
+
+# Shell helpers whose first argument is a pattern matched against daemon logs.
+SHELL_HELPERS = ("count_log_pattern", "assert_zero_count")
+
+# A literal run shorter than this is too weak to search for meaningfully.
+MIN_ANCHOR = 8
+
+
+META = set("[](){}?*+.^$")
+
+
+def literal_anchors(pattern: str) -> list[str]:
+    """Longest literal run of each alternation branch of a grep pattern.
+
+    Walks the pattern rather than substituting, because escaping has to be
+    resolved in the same pass as the split: `\\.` is a literal dot and ends
+    nothing, while a bare `.` is a wildcard and ends the run. Unescaping first
+    and splitting after would conflate the two and treat `directory.mode` as
+    though it were literal text.
+    """
+    branches, current, i = [], [], 0
+    while i < len(pattern):
+        ch = pattern[i]
+        if ch == "\\" and i + 1 < len(pattern):
+            nxt = pattern[i + 1]
+            if nxt == "|":  # BRE alternation
+                branches.append("".join(current))
+                current = []
+            elif nxt in "wsdbWSDB":  # a character class, not a literal
+                current.append("\0")
+            else:
+                current.append(nxt)
+            i += 2
+            continue
+        if ch == "|":  # ERE alternation
+            branches.append("".join(current))
+            current = []
+        elif ch in META:
+            current.append("\0")
+        else:
+            current.append(ch)
+        i += 1
+    branches.append("".join(current))
+
+    anchors = []
+    for branch in branches:
+        runs = [r.strip() for r in branch.split("\0")]
+        runs = [r for r in runs if r]
+        if runs:
+            anchors.append(max(runs, key=len))
+    return anchors
+
+
+def python_candidates() -> list[tuple[Path, int, str]]:
+    """`"literal" in line` tests in testing/ python."""
+    found = []
+    for path in sorted(TESTING.rglob("*.py")):
+        for n, line in enumerate(path.read_text(encoding="utf-8").splitlines(), 1):
+            for m in re.finditer(r'"([^"]+)"\s+in\s+line\b', line):
+                found.append((path, n, m.group(1)))
+    return found
+
+
+def shell_candidates() -> list[tuple[Path, int, str]]:
+    """Literal first argument to a log-matching shell helper."""
+    helpers = "|".join(SHELL_HELPERS)
+    # Quoted literal only; a variable argument is resolved elsewhere and is
+    # reported as unscannable rather than silently skipped.
+    literal = re.compile(rf"\b(?:{helpers})\s+(\"[^\"$]+\"|'[^']+')")
+    variable = re.compile(rf"\b(?:{helpers})\s+[\"']?\$")
+    found = []
+    for path in sorted(TESTING.rglob("*.sh")):
+        for n, line in enumerate(path.read_text(encoding="utf-8").splitlines(), 1):
+            if line.lstrip().startswith("#"):
+                continue
+            for m in literal.finditer(line):
+                found.append((path, n, m.group(1)[1:-1]))
+            if variable.search(line):
+                found.append((path, n, None))
+    return found
+
+
+def pattern_table_candidates() -> list[tuple[Path, int, str]]:
+    """Bash associative-array keys used as log patterns.
+
+    A suite that iterates a table of patterns into a log-matching helper hides
+    every string behind a variable, so the helper rule above sees only
+    `count_log_pattern "$pat"` and reports it unscannable. The keys are the
+    patterns; read them where they are written.
+    """
+    key = re.compile(r'^\s*\[\s*"([^"$]+)"\s*\]=')
+    found = []
+    for path in sorted(TESTING.rglob("*.sh")):
+        text = path.read_text(encoding="utf-8")
+        if not any(h in text for h in SHELL_HELPERS):
+            continue
+        for n, line in enumerate(text.splitlines(), 1):
+            if line.lstrip().startswith("#"):
+                continue
+            m = key.match(line)
+            if m:
+                found.append((path, n, m.group(1)))
+    return found
+
+
+def grep_candidates() -> list[tuple[Path, int, str]]:
+    """Literal grep patterns whose input is daemon log text.
+
+    Scoped by what the grep READS, not by what the file mentions. A suite
+    greps several unrelated sources — its own analyzer output, fipsctl JSON,
+    Tor's log, ping output — and only the daemon's log has to correspond to a
+    string in src/. Two shapes qualify: a grep piped directly from
+    `docker logs`, and a grep fed a variable that was assigned from it.
+    """
+    grep_lit = r"\bgrep\b[^|;]*?\s(\"[^\"$]+\"|'[^'$]+')"
+    assign = re.compile(r"(\w+)=\"?\$\(\s*docker logs\b")
+    found = []
+    for path in sorted(TESTING.rglob("*.sh")):
+        text = path.read_text(encoding="utf-8")
+        if "docker logs" not in text:
+            continue
+        log_vars = set(assign.findall(text))
+        # A grep reading one of those variables, by herestring or by pipe.
+        var_alt = "|".join(re.escape(v) for v in log_vars) or r"\0"
+        reads_var = re.compile(rf"[\"']?\$\{{?(?:{var_alt})\b")
+        for n, line in enumerate(text.splitlines(), 1):
+            if line.lstrip().startswith("#"):
+                continue
+            if "docker logs" not in line and not reads_var.search(line):
+                continue
+            for m in re.finditer(grep_lit, line):
+                found.append((path, n, m.group(1)[1:-1]))
+    return found
+
+
+def main() -> int:
+    verbose = "--verbose" in sys.argv
+    src_text = "\n".join(
+        p.read_text(encoding="utf-8", errors="replace")
+        for p in SRC.rglob("*.rs")
+    )
+
+    candidates = (
+        python_candidates()
+        + shell_candidates()
+        + pattern_table_candidates()
+        + grep_candidates()
+    )
+    dead, checked, exempt, unscannable = [], 0, 0, 0
+
+    for path, lineno, raw in candidates:
+        rel = path.relative_to(REPO)
+        if raw is None:
+            unscannable += 1
+            if verbose:
+                print(f"  skip {rel}:{lineno}: pattern comes from a variable")
+            continue
+        if raw in ALLOWED:
+            exempt += 1
+            if verbose:
+                print(f"  allow {rel}:{lineno}: {raw!r} ({ALLOWED[raw]})")
+            continue
+        anchors = literal_anchors(raw)
+        # An alternation may mix daemon strings with runtime ones, so the
+        # allowlist applies per branch and not only to the whole pattern.
+        if any(a in ALLOWED for a in anchors):
+            exempt += 1
+            if verbose:
+                print(f"  allow {rel}:{lineno}: {raw!r} (branch in ALLOWED)")
+            anchors = [a for a in anchors if a not in ALLOWED]
+        usable = [a for a in anchors if len(a) >= MIN_ANCHOR]
+        if not usable:
+            unscannable += 1
+            if verbose:
+                print(f"  skip {rel}:{lineno}: {raw!r} has no literal run >= {MIN_ANCHOR}")
+            continue
+        checked += 1
+        # Every alternation branch must be live: one dead branch is a matcher
+        # that has silently narrowed.
+        for anchor in usable:
+            if anchor not in src_text:
+                dead.append((rel, lineno, raw, anchor))
+            elif verbose:
+                print(f"  ok   {rel}:{lineno}: {anchor!r}")
+
+    print(
+        f"log-string check: {checked} matched, {exempt} allowed, "
+        f"{unscannable} unscannable, {len(dead)} dead"
+    )
+    if dead:
+        print("\nStrings matched against daemon logs that src/ never emits:\n")
+        for rel, lineno, raw, anchor in dead:
+            print(f"  {rel}:{lineno}")
+            print(f"      pattern: {raw!r}")
+            print(f"      missing: {anchor!r}")
+        print(
+            "\nEither correct the string to what the daemon emits, or add it to "
+            "ALLOWED\nin this script with the reason it does not come from src/."
+        )
+        return 1
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/testing/ci-local.sh b/testing/ci-local.sh
index 5410a34..cee312c 100755
--- a/testing/ci-local.sh
+++ b/testing/ci-local.sh
@@ -1059,6 +1059,16 @@ run_ci_parity() {
     record "ci-parity" $rc
 }
 
+# Every daemon log string a test matches on must still be emitted by src/.
+# A stale one does not fail — it stops observing, and an expect-zero assertion
+# built on it then passes for the wrong reason.
+run_log_strings() {
+    local rc=0
+    info "[log-strings] Checking test log matchers against the strings src/ emits"
+    python3 "$SCRIPT_DIR/check-log-strings.py" || rc=$?
+    record "log-strings" $rc
+}
+
 # ── Main ───────────────────────────────────────────────────────────────────
 
 main() {
@@ -1071,6 +1081,7 @@ main() {
     # --build-only are gated too: a divergence invalidates any claim that a
     # local run means what a GitHub run means, whichever subset was asked for.
     run_ci_parity
+    run_log_strings
 
     if [[ "$TEST_ONLY" == true ]]; then
         run_tests
diff --git a/testing/interop/interop-test.sh b/testing/interop/interop-test.sh
index b2e0866..f240daf 100755
--- a/testing/interop/interop-test.sh
+++ b/testing/interop/interop-test.sh
@@ -846,10 +846,10 @@ declare -A GLOBAL_PATTERNS=(
     ["ERROR"]="error-level log lines"
     ["unknown FMP version|Unknown FMP version"]="unknown-FMP-version drops"
     ["MMP link teardown"]="MMP link teardowns"
-    ["Excessive decrypt failures"]="excessive-decrypt-failure removals"
+    ["Excessive decryption failures"]="excessive-decryption-failure removals"
     ["Session AEAD decryption failed"]="FSP AEAD decrypt failures"
     ["Rekey msg2 processing failed"]="rekey msg2 failures"
-    ["Handshake failed|handshake failed|Handshake error"]="handshake failures"
+    ["Handshake failed|handshake failed"]="handshake failures"
 )
 
 for pat in "${!GLOBAL_PATTERNS[@]}"; do
diff --git a/testing/lib/log_analysis.py b/testing/lib/log_analysis.py
index ffa33bb..7de162f 100644
--- a/testing/lib/log_analysis.py
+++ b/testing/lib/log_analysis.py
@@ -149,7 +149,7 @@ def _analyze_lines(result: AnalysisResult, source: str, log_text: str):
         if "Session established" in line:
             result.sessions_established.append((source, line))
         # Peer promotion
-        if "Inbound peer promoted" in line or "Outbound handshake completed" in line:
+        if "Peer promoted to active" in line or "Outbound handshake completed" in line:
             result.peers_promoted.append((source, line))
         # Peer removal
         if "Peer removed" in line:
@@ -174,7 +174,7 @@ def _analyze_lines(result: AnalysisResult, source: str, log_text: str):
         if "Rekey cutover complete" in line or "FSP rekey cutover complete" in line:
             result.rekey_cutovers.append((source, line))
         # Discovery
-        if "Initiating LookupRequest" in line or "Discovery lookup initiated" in line:
+        if "Discovery lookup initiated" in line:
             result.discovery_initiated.append((source, line))
         if "proof verified, route cached" in line:
             result.discovery_succeeded.append((source, line))
@@ -197,8 +197,18 @@ def _analyze_lines(result: AnalysisResult, source: str, log_text: str):
 
 
 def collect_docker_logs(containers: list[str]) -> dict[str, str]:
-    """Collect logs from Docker containers, stripping ANSI codes."""
+    """Collect logs from Docker containers, stripping ANSI codes.
+
+    Raises RuntimeError if any container's log could not be read. `docker
+    logs` reports a missing container on stderr and exits non-zero, so
+    without the returncode check that reply was stored as though it were the
+    node's own log and analysed as a mesh with no panics, no errors and no
+    sessions — which reads exactly like a clean run. Substituting "" on the
+    exception path has the same effect. Mirrors the fix already landed in
+    chaos/sim/logs.py's collect_logs.
+    """
     logs = {}
+    failed = []
     for name in containers:
         try:
             result = subprocess.run(
@@ -207,10 +217,26 @@ def collect_docker_logs(containers: list[str]) -> dict[str, str]:
                 text=True,
                 timeout=30,
             )
-            raw = result.stdout + result.stderr
-            logs[name] = strip_ansi(raw)
-        except (subprocess.TimeoutExpired, Exception):
-            logs[name] = ""
+        except Exception as e:
+            print(f"failed to collect logs from {name}: {e}", file=sys.stderr)
+            failed.append(name)
+            continue
+
+        if result.returncode != 0:
+            print(
+                f"docker logs {name} exited {result.returncode}: "
+                f"{result.stderr.strip()}",
+                file=sys.stderr,
+            )
+            failed.append(name)
+            continue
+
+        # A container's own stderr arrives on our stderr, so on the success
+        # path both streams are log content.
+        logs[name] = strip_ansi(result.stdout + result.stderr)
+
+    if failed:
+        raise RuntimeError("could not read logs from: " + ", ".join(failed))
     return logs
 
 
diff --git a/testing/nat/scripts/nat-test.sh b/testing/nat/scripts/nat-test.sh
index 2ae48a0..3628e87 100755
--- a/testing/nat/scripts/nat-test.sh
+++ b/testing/nat/scripts/nat-test.sh
@@ -316,7 +316,7 @@ require_bootstrap_activity() {
     local container="$1"
     local logs
     logs="$(docker logs "$container" 2>&1 || true)"
-    if ! grep -Eq "bootstrap failed|Started Nostr( UDP)? NAT traversal attempt" <<<"$logs"; then
+    if ! grep -Eq "Started Nostr( UDP)? NAT traversal attempt" <<<"$logs"; then
         echo "Expected bootstrap activity in ${container} logs" >&2
         return 1
     fi
diff --git a/testing/static/scripts/rekey-test.sh b/testing/static/scripts/rekey-test.sh
index 0c7a72b..eab2b2a 100755
--- a/testing/static/scripts/rekey-test.sh
+++ b/testing/static/scripts/rekey-test.sh
@@ -491,7 +491,7 @@ assert_min_count "Peer FSP new-epoch frame authenticated" 1 \
 assert_zero_count "PANIC\|panicked" "Panics"
 assert_zero_count "ERROR" "Errors"
 assert_zero_count "MMP link teardown" "Spurious link teardowns"
-assert_zero_count "Excessive decrypt failures" \
+assert_zero_count "Excessive decryption failures" \
     "Excessive decrypt failure removals"
 assert_zero_count "Rekey msg2 processing failed" "Rekey msg2 failures"
 assert_zero_count "Session AEAD decryption failed" \