Distinguishable output and failure reports for gradle integrations tests

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/BaseGradleIT.kt

@@ -427,12 +427,16 @@ abstract class BaseGradleIT {
             result = runProcess(cmd, projectDir, env, buildOptions)
             CompiledProject(this, result.output, result.exitCode).check()
         } catch (t: Throwable) {
-            println("<=== Test build: ${this.projectName} $cmd ===>")
+            println("<=== Test build: $projectName $cmd ===>")
 
             // to prevent duplication of output
             if (!options.forceOutputToStdout && result != null) {
-                println(result.output)
+                result.output
+                    .split("\n")
+                    .map { "    |test output $projectName|$it" }
+                    .forEach(::println)
             }
+
             throw t
         }
     }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/KlibBasedMppIT.kt

@@ -359,8 +359,12 @@ class KlibBasedMppIT : BaseGradleIT() {
             val itemsLine = output.lines().single { "###$printingTaskName" in it }.substringAfter(printingTaskName)
             // NOTE: This does not work for commonized libraries, they may contain the ',' naturally
             val items = itemsLine.removeSurrounding("[", "]").split(", ").toSet()
-            checkAnyItemsContains.forEach { pattern -> assertTrue { items.any { pattern in it } } }
-            checkNoItemContains.forEach { pattern -> assertFalse { items.any { pattern in it } } }
+            checkAnyItemsContains.forEach { pattern ->
+                assertTrue(items.any { pattern in it }, "Couldn't find pattern `$pattern` in the output")
+            }
+            checkNoItemContains.forEach { pattern ->
+                assertFalse(items.any { pattern in it }, "Pattern '$pattern' should NOT be present in the output")
+            }
         }
     }
 }