Merge pull request #14906 from nik9000/gradle_empty_dir

Survive missing directories

buildSrc/src/main/groovy/org/elasticsearch/gradle/BuildPlugin.groovy

@@ -288,7 +288,11 @@ class BuildPlugin implements Plugin<Project> {
             project.tasks.withType(JavaCompile) {
                 options.fork = true
                 options.forkOptions.executable = new File(project.javaHome, 'bin/javac')
-                options.compilerArgs << '-Werror' << '-Xlint:all' << '-Xdoclint:all' << '-Xdoclint:-missing'
+                /*
+                 * -path because gradle will send in paths that don't always exist.
+                 * -missing because we have tons of missing @returns and @param.
+                 */
+                options.compilerArgs << '-Werror' << '-Xlint:all,-path' << '-Xdoclint:all' << '-Xdoclint:-missing'
                 options.encoding = 'UTF-8'
             }
         }

buildSrc/src/main/groovy/org/elasticsearch/gradle/precommit/PrecommitTasks.groovy

@@ -111,7 +111,11 @@ class PrecommitTasks {
         task.outputs.file(successMarker)
         task.executable = new File(project.javaHome, 'bin/java')
         task.doFirst({
-            task.args('-cp', testClasspath.asPath, 'org.elasticsearch.bootstrap.JarHell')
+            /* JarHell doesn't like getting directories that don't exist but
+              gradle isn't especially careful about that. So we have to do it
+              filter it ourselves. */
+            def taskClasspath = testClasspath.filter { it.exists() }
+            task.args('-cp', taskClasspath.asPath, 'org.elasticsearch.bootstrap.JarHell')
         })
         if (task.logger.isInfoEnabled() == false) {
             task.standardOutput = new ByteArrayOutputStream()