src/jdk.jlink/share/classes/jdk/tools/jlink/internal/Jlink.java

@@ -25,11 +25,13 @@
 package jdk.tools.jlink.internal;
 
 import java.lang.module.Configuration;
 import java.lang.module.ModuleFinder;
 import java.nio.ByteOrder;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;

@@ -174,11 +176,28 @@
             this.output = output;
             this.modulepaths = modulepaths;
             this.modules = Objects.requireNonNull(modules);
             this.limitmods = Objects.requireNonNull(limitmods);
             this.endian = Objects.requireNonNull(endian);
-            this.finder = moduleFinder();
+            ModuleFinder finder = moduleFinder(modulepaths, limitmods, modules);
+            if (! finder.find("java.base").isPresent()) {
+                Path sysPath = getDefaultModulePath();
+                if (sysPath != null) {
+                    this.modulepaths.add(sysPath);
+                }
+                // if java.base is still not found, error will be thrown later!
+                finder = moduleFinder(modulepaths, limitmods, modules);
+            }
+            this.finder = finder;
+        }
+
+        /**
+         * @return the system module path or null
+         */
+        public static Path getDefaultModulePath() {
+            Path jmods = Paths.get(System.getProperty("java.home"), "jmods");
+            return Files.isDirectory(jmods)? jmods : null;
         }
 
         /**
          * @return the modulepaths
          */

@@ -242,11 +261,12 @@
             return Configuration.empty().resolve(finder,
                                                  ModuleFinder.of(),
                                                  modules);
         }
 
-        private ModuleFinder moduleFinder() {
+        private static ModuleFinder moduleFinder(List<Path> modulepaths,
+                Set<String> limitmods, Set<String> modules) {
             Path[] entries = modulepaths.toArray(new Path[0]);
             ModuleFinder finder = ModulePath.of(Runtime.version(), true, entries);
             if (!limitmods.isEmpty()) {
                 finder = JlinkTask.limitFinder(finder, limitmods, modules);
             }