Merge pull request #8413 from rabbitmq/mergify/bp/v3.12.x/pr-8344

Add looking_glass (backport #8344)

Author: michaelklishin

BUILD.bazel

@@ -137,7 +137,10 @@ plt(
 
 PLUGINS = all_plugins(
     rabbitmq_workspace = "",
-)
+) + select({
+    "@rules_erlang//:debug_build": ["@looking_glass//:erlang_app"],
+    "//conditions:default": [],
+})
 
 rabbitmq_home(
     name = "broker-home",

MODULE.bazel

@@ -34,6 +34,13 @@ bazel_dep(
     version = "3.10.5",
 )
 
+bazel_dep(
+    name = "com_github_rabbitmq_looking_glass",
+    version = "0.2.1",
+    repo_name = "looking_glass",
+    dev_dependency = True,
+)
+
 erlang_config = use_extension(
     "@rules_erlang//bzlmod:extensions.bzl",
     "erlang_config",

deps/rabbit/BUILD.bazel

@@ -236,16 +236,19 @@ plt(
     name = "deps_plt",
     apps = [
         "mnesia",  # keep
+        "runtime_tools",  # keep
     ],
     for_target = ":erlang_app",
     ignore_warnings = True,
     plt = "//:base_plt",
+    deps = [
+        "@looking_glass//:erlang_app",  # keep
+    ],
 )
 
 dialyze(
     name = "dialyze",
-    # A few `lg` functions are unknown
-    dialyzer_opts = without("-Wunknown", RABBITMQ_DIALYZER_OPTS),
+    dialyzer_opts = RABBITMQ_DIALYZER_OPTS,
     plt = ":deps_plt",
     target = ":erlang_app",
 )

deps/rabbit/src/rabbit_looking_glass.erl

@@ -78,7 +78,7 @@ trace_qq() ->
                             ]
             )),
     timer:sleep(10000),
-    lg:stop(),
+    _ = lg:stop(),
     profile().
 
 profile() ->