Reproducer

libraries/stdlib/test/collections/MapTest.kt

diff --git a/libraries/stdlib/test/collections/MapTest.kt b/libraries/stdlib/test/collections/MapTest.kt
index a99f519..2efb3aa 100644
--- a/libraries/stdlib/test/collections/MapTest.kt
+++ b/libraries/stdlib/test/collections/MapTest.kt
@@ -12,6 +12,12 @@
 import kotlin.math.pow
 
 class MapTest {
+    @Test fun testBuilder() {
+        val m = buildMap {
+            this["key"] = "value"
+        }
+        println(m)
+    }
 
     @Test fun getOrElse() {
         val data = mapOf<String, Int>()