[debug] it's possible to inspect array elements in debugger

backend.native/debugger-tests/src/main/kotlin/org/jetbrains/kotlin/compiletest/Matchers.kt

@@ -133,7 +133,16 @@ private class LldbSessionSpecification private constructor(
                 && commands.zip(executedCommands).all { (cmd, h) -> h == "(lldb) $cmd" }
 
         if (!responsesMatch) {
-            fail("Responses do not match commands.\nResponses: $executedCommands\nCommands: $commands")
+            val message = """
+Responses do not match commands.
+
+COMMANDS: $commands
+RESPONSES: $executedCommands
+
+FULL SESSION:
+$output
+"""
+            fail(message)
         }
 
         for ((patternBody, command) in patterns.zip(bodies).zip(executedCommands)) {

backend.native/debugger-tests/src/test/kotlin/org/jetbrains/kotlin/compiletest/LldbTests.kt

@@ -94,4 +94,20 @@ class LldbTests {
         (ObjHeader *) xs = [1, 2, 3]
         (ObjHeader *) ys = [Point(x=1, y=2), null]
     """)
+
+    @Test
+    fun `can inspect array children`() = lldbTest("""
+        fun main(args: Array<String>) {
+            val xs = intArrayOf(3, 5, 8)
+            return
+        }
+
+        data class Point(val x: Int, val y: Int)
+    """, """
+        > type summary add "ObjHeader *" --inline-children
+        > b main.kt:3
+        > r
+        > fr var xs
+        (ObjHeader *) xs = [..] (0 = 3, 1 = 5, 2 = 8)
+    """)
 }