If the state location is not accessible, use MemoryByteStore.

pkg/analyzer_cli/lib/src/driver.dart

Index: pkg/analyzer_cli/lib/src/driver.dart
diff --git a/pkg/analyzer_cli/lib/src/driver.dart b/pkg/analyzer_cli/lib/src/driver.dart
index 0c4f86d073d665ab0213fd718a289a4aa57a6366..f3c57a2ae99c0a6f00728150a8dd329cfffa696c 100644
--- a/pkg/analyzer_cli/lib/src/driver.dart
+++ b/pkg/analyzer_cli/lib/src/driver.dart
@@ -78,13 +78,7 @@ class Driver implements CommandLineStarter {
       new PerformanceTag("Driver._analyzeAll");
 
   static ByteStore analysisDriverMemoryByteStore = new MemoryByteStore();
-  static ByteStore analysisDriverFileByteStore = new MemoryCachingByteStore(
-      new EvictingFileByteStore(
-          PhysicalResourceProvider.INSTANCE
-              .getStateLocation('.analysis-driver')
-              .path,
-          1024 * 1024 * 1024 /*1 GiB*/),
-      64 * 1024 * 1024 /*64 MiB*/);
+  static ByteStore analysisDriverFileByteStore = _createFileByteStore();
 
   /// The plugins that are defined outside the `analyzer_cli` package.
   List<Plugin> _userDefinedPlugins = <Plugin>[];
@@ -794,6 +788,22 @@ class Driver implements CommandLineStarter {
     context.analysisOptions = analysisOptions;
   }
 
+  /**
+   * If the state location can be accessed, return the file byte store,
+   * otherwise return the memory byte store.
+   */
+  static ByteStore _createFileByteStore() {
+    const int M = 1024 * 1024 /*1 MiB*/;
+    const int G = 1024 * 1024 * 1024 /*1 GiB*/;
+    file_system.Folder stateLocation =
+        PhysicalResourceProvider.INSTANCE.getStateLocation('.analysis-driver');
+    if (stateLocation == null) {
+      return new MemoryByteStore();
+    }
+    return new MemoryCachingByteStore(
+        new EvictingFileByteStore(stateLocation.path, G), 64 * M);
+  }
+
   /// Perform a deep comparison of two string lists.
   static bool _equalLists(List<String> l1, List<String> l2) {
     if (l1.length != l2.length) {