anchor.diff:      }
   
       // Compute and record build fingerprint.
  -    try {
  -      final Fingerprint fingerprint = await makeFingerprint();
  -      await fingerprintFile.writeAsString(fingerprint.toJson());
  -    } catch (e, s) {
  -      // Log exception and continue, this step is a performance improvement only.
  -      printStatus('Error during AOT snapshot fingerprinting: $e\n$s');
  -    }
  -
  +    await _writeFingerprint(snapshotType, outputPaths, depfilePath, mainPath, fingerprintPath);
       return 0;
     }
   
  
positive.code:     return true;
    }
  
    Future<Null> _writeFingerprint(SnapshotType type, String outputSnapshotPath, String depfilePath, String mainPath, String fingerprintPath) async {
      try {
        final Set<String> inputFilePaths = await readDepfile(depfilePath)
          ..addAll(<String>[outputSnapshotPath, mainPath]);
        final Fingerprint fingerprint = createFingerprint(type, mainPath, inputFilePaths);
        await fs.file(fingerprintPath).writeAsString(fingerprint.toJson());
      } catch (e, s) {
  
negative.code:       ]);
      }
  
      final String fingerprintPath = '$dependencies.fingerprint';
      final SnapshotType snapshotType = new SnapshotType(platform, buildMode);
      if (!await _isBuildRequired(snapshotType, outputPaths, depfilePath, mainPath, fingerprintPath)) {
        printTrace('Skipping AOT snapshot build. Fingerprint match.');
        return 0;
      }
  
      String entrypointPath = mainPath;
      if (previewDart2) {
        final CompilerOutput compilerOutput = await kernelCompiler.compile(
          sdkRoot: artifacts.getArtifactPath(Artifact.flutterPatchedSdkPath),
  