[Gradle] GradleKotlinCompilerRunner: Be lenient to isolated classpaths

^KT-50592

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/GradleKotlinCompilerRunner.kt

@@ -16,7 +16,6 @@ import org.gradle.workers.WorkQueue
 import org.jetbrains.kotlin.build.report.metrics.BuildMetricsReporter
 import org.jetbrains.kotlin.build.report.metrics.BuildTime
 import org.jetbrains.kotlin.build.report.metrics.measure
-import org.jetbrains.kotlin.cli.common.CompilerSystemProperties
 import org.jetbrains.kotlin.cli.common.arguments.*
 import org.jetbrains.kotlin.cli.common.messages.MessageCollector
 import org.jetbrains.kotlin.daemon.client.CompileServiceSession
@@ -32,8 +31,7 @@ import org.jetbrains.kotlin.gradle.plugin.internal.state.TaskLoggers
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinWithJavaTarget
 import org.jetbrains.kotlin.gradle.plugin.statistics.KotlinBuildStatsService
 import org.jetbrains.kotlin.gradle.tasks.*
-import org.jetbrains.kotlin.gradle.tasks.InspectClassesForMultiModuleIC
-import org.jetbrains.kotlin.gradle.tasks.TaskOutputsBackup
+import org.jetbrains.kotlin.gradle.utils.IsolatedKotlinClasspathClassCastException
 import org.jetbrains.kotlin.gradle.utils.archivePathCompatible
 import org.jetbrains.kotlin.gradle.utils.newTmpFile
 import org.jetbrains.kotlin.gradle.utils.relativeOrCanonical
@@ -273,8 +271,19 @@ internal open class GradleCompilerRunner(
 
             gradle.taskGraph.allTasks.forEach { task ->
                 val project = task.project
-                // TODO REVIEW: Should this fail or be lenient on isolated classpaths (and therefore failing cast)?
-                if (project.multiplatformExtensionOrNull != null) {
+
+                /*
+                Ignoring isolated classpath:
+                An inaccessible project is not a fatal issue here. Missing information will "only" lead to non-incremental
+                compilation. We expect the user to be warned about this misconfiguration during configuration phase.
+                 */
+                val multiplatformExtension = try {
+                    project.multiplatformExtensionOrNull
+                } catch (e: IsolatedKotlinClasspathClassCastException) {
+                    null
+                }
+
+                if (multiplatformExtension != null) {
                     // Just record this, we'll process them later
                     val tasksInProject = multiplatformProjectTasks[project] ?: mutableSetOf()
                     tasksInProject.add(task.name)