Avoid unsafe rb_inspect call

Author: jhawthorn

ext/vernier/vernier.cc

@@ -939,13 +939,6 @@ class ThreadTable {
                     if (thread.state == Thread::State::RUNNING) {
                         thread.pthread_id = pthread_self();
                         thread.native_tid = get_native_thread_id();
-                        if (thread.name == "") {
-                            // rb_inspect should be safe here, as RUNNING should correspond to RESUMED hook from internal_thread_event_cb
-                            // which is called with GVL per https://github.com/ruby/ruby/blob/v3_3_0/include/ruby/thread.h#L247-L248
-                            VALUE thread_str = rb_inspect(th);
-                            if (RTEST(thread_str))
-                                thread.name = StringValueCStr(thread_str);
-                        }
                     } else {
                         thread.pthread_id = 0;
                         thread.native_tid = 0;

test/test_time_collector.rb

@@ -148,6 +148,21 @@ def test_raised_exceptions_will_output
     assert File.exist?(output_file)
   end
 
+  class ThreadWithInspect < ::Thread
+    def inspect
+      raise "boom!"
+    end
+  end
+
+  def test_thread_with_inspect
+    result = Vernier.trace do
+      th1 = ThreadWithInspect.new { sleep 0.01 }
+      th1.join
+    end
+
+    assert_valid_result result
+  end
+
   def assert_similar expected, actual
     delta_ratio =
       if SLOW_RUNNER