workspace: fix wrong default value for fetch_registry_index_during_builds

Author: pietroalbini

CHANGELOG.md

@@ -5,6 +5,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Fixed
+
+- The default value for `WorkspaceBuilder::fetch_registry_index_during_builds`
+  was mistakenly set to `false` instead of `true` by default.
+
 ## [0.3.1] - 2019-09-23
 
 ### Fixed

src/workspace.rs

@@ -42,7 +42,7 @@ impl WorkspaceBuilder {
             sandbox_image: None,
             command_timeout: DEFAULT_COMMAND_TIMEOUT,
             command_no_output_timeout: DEFAULT_COMMAND_NO_OUTPUT_TIMEOUT,
-            fetch_registry_index_during_builds: false,
+            fetch_registry_index_during_builds: true,
             running_inside_docker: false,
             fast_init: false,
         }