diff --git a/test/features/meshtastic/mesh_chat_controller_test.dart b/test/features/meshtastic/mesh_chat_controller_test.dart
index 88a3936aa..977c934f0 100644
--- a/test/features/meshtastic/mesh_chat_controller_test.dart
+++ b/test/features/meshtastic/mesh_chat_controller_test.dart
@@ -61,6 +61,23 @@ void main() {
   Future<void> settle() =>
       Future<void>.delayed(const Duration(milliseconds: 150));
 
+  /// Waits until [store] holds [expected] messages.
+  ///
+  /// `_add` writes fire-and-forget and only adopts a message into the in-memory
+  /// list once the insert answers (mesh_chat_controller.dart:322-328), so both
+  /// halves of what these tests assert land *after* the controller has been
+  /// handed the packet. A fixed delay is therefore a guess about how fast the
+  /// machine is: 150 ms was enough on a laptop and not on CI, where the last
+  /// dozen inserts arrived after the test had already closed the database and
+  /// the failure read as `This database has already been closed`.
+  Future<void> drained(MeshStore store, int expected) async {
+    final deadline = DateTime.now().add(const Duration(seconds: 10));
+    while (DateTime.now().isBefore(deadline)) {
+      if ((await store.messages(limit: 100000)).length >= expected) return;
+      await Future<void>.delayed(const Duration(milliseconds: 10));
+    }
+  }
+
   test('keeps the newest messages first', () async {
     final (controller, service, _) = await makeController();
     for (var i = 0; i < 10; i++) {
@@ -78,7 +95,7 @@ void main() {
     for (var i = 0; i < MeshChatController.windowSize + 20; i++) {
       service.messages.add(message('m$i', seconds: i));
     }
-    await settle();
+    await drained(store, MeshChatController.windowSize + 20);
 
     expect(controller.messages, hasLength(MeshChatController.windowSize));
     // The store keeps everything — the window is a view, not a retention cap.
@@ -91,7 +108,7 @@ void main() {
   test('persists the log and reloads it after a restart', () async {
     final (controller, service, store) = await makeController();
     service.messages.add(message('hello'));
-    await settle();
+    await drained(store, 1);
     controller.dispose();
 
     final (restored, _, _) = await makeController(store);
diff --git a/test/tool/colorize_logs_test.dart b/test/tool/colorize_logs_test.dart
index 103fcaeae..5d97bc6a7 100644
--- a/test/tool/colorize_logs_test.dart
+++ b/test/tool/colorize_logs_test.dart
@@ -15,17 +15,21 @@ const _esc = 27;
 /// Runs the script over [input]. Without a pty, stdout is not a terminal.
 String run(String input, {bool tty = false}) {
   final script = '${Directory.current.path}/tool/internal/colorize_logs.sh';
+  final piped = 'printf %s ${_quote(input)} | $script';
+  // `script` lends the pipeline a pty, which is the only way to exercise the
+  // branch that decides whether to emit anything at all — and its argument
+  // order is the opposite on the two platforms this repository builds on.
+  // BSD takes the typescript file first and the command after it; util-linux
+  // wants the command behind `-c` and the file last. Written for BSD only, it
+  // passed on a laptop and hung Linux CI into a failure with no message.
   final result = tty
-      // `script` lends the pipeline a pty, which is the only way to exercise
-      // the branch that decides whether to emit anything at all.
-      ? Process.runSync('script', [
-          '-q',
-          '/dev/null',
-          'bash',
-          '-c',
-          'printf %s ${_quote(input)} | $script',
-        ])
-      : Process.runSync('bash', ['-c', 'printf %s ${_quote(input)} | $script']);
+      ? Process.runSync(
+          'script',
+          Platform.isMacOS
+              ? ['-q', '/dev/null', 'bash', '-c', piped]
+              : ['-q', '-c', piped, '/dev/null'],
+        )
+      : Process.runSync('bash', ['-c', piped]);
   expect(result.exitCode, 0, reason: result.stderr.toString());
   return result.stdout.toString();
 }
diff --git a/tool/commit.sh b/tool/commit.sh
index dbcac3837..46f7820f0 100755
--- a/tool/commit.sh
+++ b/tool/commit.sh
@@ -301,7 +301,13 @@ if ((run_gates)); then
   note 'inputs, so an unchanged tree costs seconds instead of a minute.'
   printf '\n'
   if tool/check.sh; then
-    ok 'every gate passed — this is what CI will do'
+    ok "every gate passed, on $(uname -s)"
+    # Said, because the difference has already cost a red CI: this runs CI's
+    # command list on *this* machine, and the runner is Linux. A test that
+    # shells out meets a different sed, a different awk and a different
+    # `script`, and passes here while failing there.
+    [[ "$(uname -s)" == Linux ]] ||
+      note 'CI runs Linux — a test that shells out can still differ there'
   else
     block 'a gate failed — CI will fail the same way'
   fi