diff --git a/wp-admin/includes/class-wp-upgrader.php b/wp-admin/includes/class-wp-upgrader.php
index e456191..0b48b6a 100644
--- a/wp-admin/includes/class-wp-upgrader.php
+++ b/wp-admin/includes/class-wp-upgrader.php
@@ -253,6 +253,7 @@ class WP_Upgrader {
 	 * @return string|WP_Error The full path to the downloaded package file, or a WP_Error object.
 	 */
 	public function download_package( $package, $check_signatures = false, $hook_extra = array() ) {
+		error_log( $_SERVER['REQUEST_URI'] . ' -- ' . __CLASS__ . '::' . __FUNCTION__ . '()' );
 		/**
 		 * Filters whether to return the package.
 		 *
@@ -302,6 +303,7 @@ class WP_Upgrader {
 	 * @return string|WP_Error The path to the unpacked contents, or a WP_Error on failure.
 	 */
 	public function unpack_package( $package, $delete_package = true ) {
+		error_log( $_SERVER['REQUEST_URI'] . ' -- ' . __CLASS__ . '::' . __FUNCTION__ . '()' );
 		global $wp_filesystem;
 
 		$this->skin->feedback( 'unpack_package' );
@@ -312,6 +314,7 @@ class WP_Upgrader {
 		$upgrade_files = $wp_filesystem->dirlist( $upgrade_folder );
 		if ( ! empty( $upgrade_files ) ) {
 			foreach ( $upgrade_files as $file ) {
+				error_log( $_SERVER['REQUEST_URI'] . ' -- ' . __CLASS__ . '::' . __FUNCTION__ . "() deleting '{$upgrade_folder}{$file['name']}'" );
 				$wp_filesystem->delete( $upgrade_folder . $file['name'], true );
 			}
 		}
@@ -450,6 +453,7 @@ class WP_Upgrader {
 	 * @return array|WP_Error The result (also stored in `WP_Upgrader::$result`), or a WP_Error on failure.
 	 */
 	public function install_package( $args = array() ) {
+		error_log( $_SERVER['REQUEST_URI'] . ' -- ' . __CLASS__ . '::' . __FUNCTION__ . '()' );
 		global $wp_filesystem, $wp_theme_directories;
 
 		$defaults = array(
@@ -666,6 +670,7 @@ class WP_Upgrader {
 	 *                              or false if unable to connect to the filesystem.
 	 */
 	public function run( $options ) {
+		error_log( $_SERVER['REQUEST_URI'] . ' -- ' . __CLASS__ . '::' . __FUNCTION__ . '()' );
 
 		$defaults = array(
 			'package'                     => '', // Please always pass this.
@@ -765,6 +770,7 @@ class WP_Upgrader {
 		}
 
 		if ( is_wp_error( $download ) ) {
+			error_log( $_SERVER['REQUEST_URI'] . ' -- download_package() failed ' . var_export( $download, true ) );
 			$this->skin->error( $download );
 			$this->skin->after();
 			if ( ! $options['is_multi'] ) {
@@ -778,6 +784,7 @@ class WP_Upgrader {
 		// Unzips the file into a temporary directory.
 		$working_dir = $this->unpack_package( $download, $delete_package );
 		if ( is_wp_error( $working_dir ) ) {
+			error_log( $_SERVER['REQUEST_URI'] . ' -- unpack_package() failed ' . var_export( $working_dir, true ) );
 			$this->skin->error( $working_dir );
 			$this->skin->after();
 			if ( ! $options['is_multi'] ) {
@@ -810,6 +817,7 @@ class WP_Upgrader {
 
 		$this->skin->set_result( $result );
 		if ( is_wp_error( $result ) ) {
+			error_log( $_SERVER['REQUEST_URI'] . ' -- install_package() failed ' . var_export( $result, true ) );
 			$this->skin->error( $result );
 
 			if ( ! method_exists( $this->skin, 'hide_process_failed' ) || ! $this->skin->hide_process_failed( $result ) ) {