If the state location is not accessible, use MemoryByteStore.

pkg/analyzer_cli/lib/src/driver.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer_cli.src.driver;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io' as io;
 
@@ skipping 60 matching lines @@
   return linterNode is YamlMap && linterNode.containsKey('rules');
 }
 
 typedef Future<ErrorSeverity> _BatchRunnerHandler(List<String> args);
 
 class Driver implements CommandLineStarter {
   static final PerformanceTag _analyzeAllTag =
       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>[];
 
   /// The context that was most recently created by a call to [_analyzeAll], or
   /// `null` if [_analyzeAll] hasn't been called yet.
   InternalAnalysisContext _context;
 
   AnalysisDriver analysisDriver;
 
@@ skipping 689 matching lines @@
     }
 
     if (options.log) {
       AnalysisEngine.instance.logger = new StdLogger();
     }
 
     // Set context options.
     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) {
       return false;
     }
     for (int i = 0; i < l1.length; i++) {
       if (l1[i] != l2[i]) {
         return false;
       }
     }
@@ skipping 148 matching lines @@
     for (var package in packages) {
       var packageName = path.basename(package.path);
       var realPath = package.resolveSymbolicLinksSync();
       result[packageName] = [
         PhysicalResourceProvider.INSTANCE.getFolder(realPath)
       ];
     }
     return result;
   }
 }