Remove components if they don't exist anymore during update

Author: pietroalbini

src/rustup-dist/src/manifestation.rs

@@ -475,6 +475,7 @@ impl Update {
             rust_target_package,
             new_manifest,
             &changes,
+            notify_handler,
         );
 
         // If this is a full upgrade then the list of components to
@@ -520,6 +521,7 @@ impl Update {
         rust_target_package: &TargetedPackage,
         new_manifest: &Manifest,
         changes: &Changes,
+        notify_handler: &Fn(Notification),
     ) {
         // Add components required by the package, according to the
         // manifest
@@ -559,7 +561,14 @@ impl Update {
                         if component_is_present {
                             self.final_component_list.push(existing_component.clone());
                         } else {
-                            self.missing_components.push(existing_component.clone());
+                            // If a component is not available anymore for the target remove it
+                            // This prevents errors when trying to update to a newer version with
+                            // a removed component.
+                            self.components_to_uninstall.push(existing_component.clone());
+                            notify_handler(Notification::ComponentUnavailable(
+                                &existing_component.pkg,
+                                existing_component.target.as_ref(),
+                            ));
                         }
                     }
                 }

src/rustup-dist/src/notifications.rs

@@ -31,6 +31,7 @@ pub enum Notification<'a> {
     DownloadedManifest(&'a str, Option<&'a str>),
     DownloadingLegacyManifest,
     ManifestChecksumFailedHack,
+    ComponentUnavailable(&'a str, Option<&'a TargetTriple>),
 }
 
 impl<'a> From<rustup_utils::Notification<'a>> for Notification<'a> {
@@ -68,7 +69,8 @@ impl<'a> Notification<'a> {
             CantReadUpdateHash(_)
             | ExtensionNotInstalled(_)
             | MissingInstalledComponent(_)
-            | CachedFileChecksumFailed => NotificationLevel::Warn,
+            | CachedFileChecksumFailed
+            | ComponentUnavailable(_, _) => NotificationLevel::Warn,
             NonFatalError(_) => NotificationLevel::Error,
         }
     }
@@ -132,6 +134,13 @@ impl<'a> Display for Notification<'a> {
             ManifestChecksumFailedHack => {
                 write!(f, "update not yet available, sorry! try again later")
             }
+            ComponentUnavailable(pkg, toolchain) => {
+                if let Some(tc) = toolchain {
+                    write!(f, "component '{}' is not available anymore on target '{}'", pkg, tc)
+                } else {
+                    write!(f, "component '{}' is not available anymore", pkg)
+                }
+            }
         }
     }
 }