Added missing error message

Author: cmaglie

arduino/cores/packagemanager/install_uninstall.go

@@ -40,10 +40,8 @@ func (pm *PackageManager) UninstallPlatform(platformRelease *cores.PlatformRelea
 	}
 
 	// Safety measure
-	if safe, err := platformRelease.InstallDir.IsInsideDir(pm.PackagesDir); err != nil {
-		return fmt.Errorf("checking if plaform is installed in data dir: %s", err)
-	} else if !safe {
-		return fmt.Errorf("platform is not installed inside data dir")
+	if !pm.IsManagedPlatformRelease(platformRelease) {
+		return fmt.Errorf("%s is not managed by package manager", platformRelease)
 	}
 
 	if err := platformRelease.InstallDir.RemoveAll(); err != nil {

commands/core/install.go

@@ -95,6 +95,7 @@ func installPlatformRelease(pm *packagemanager.PackageManager, platformRelease *
 	}
 	if err != nil {
 		log.WithError(err).Error("Cannot install platform")
+		formatter.PrintError(err, "Cannot install platform")
 		os.Exit(commands.ErrGeneric)
 	}