Merge pull request #248 from sourcegraph/file-not-found

robust file-not-found check

Author: sqs

cli/store_cmds.go

@@ -269,7 +269,8 @@ func Import(buildDataFS vfs.FileSystem, stor interface{}, opt ImportOpt) error {
 			case *grapher.GraphUnitRule:
 				var data graph.Output
 				if err := readJSONFileFS(buildDataFS, rule.Target(), &data); err != nil {
-					if os.IsNotExist(err) {
+					// checking if the error begins with "file not found" is necessary because the FS may not be the actual OS FS, in which case os.IsNotExist(err) == false
+					if os.IsNotExist(err) || strings.HasPrefix(err.Error(), "file not found:") {
 						log.Printf("Warning: no build data for unit %s %s.", rule.Unit.Type, rule.Unit.Name)
 						return nil
 					}