Issue #3362143 by phenaproxima, tedbow, Wim Leers: Use the rsync file syncer by default

drupalci.yml

@@ -9,6 +9,8 @@ build:
       # Run code quality checks.
       container_command.commit-checks:
         commands:
+          # Install rsync.
+          - DEBIAN_FRONTEND=noninteractive apt-get update && apt-get install -y rsync
           # Update to Composer 2.5.5.
           - composer self-update 2.5.5
           # @todo Replace in favor of commit-code-check.sh once https://www.drupal.org/project/drupal/issues/3314100 lands.

package_manager/config/install/package_manager.settings.yml

-file_syncer: php
+# The rsync file syncer is currently the only stable file syncer and
+# should only be changed for development purposes.
+file_syncer: rsync
 executables:
   composer: ~
   rsync: ~

tests/src/Build/CoreUpdateTest.php

@@ -89,6 +89,9 @@ class CoreUpdateTest extends UpdateTestBase {
 
     // Ensure that Drupal has write-protected the site directory.
     $this->assertDirectoryIsNotWritable($this->getWebRoot() . '/sites/default');
+    // @todo Remove this when default.settings.php and default.services.yml are
+    //   ignored by Package Manager in  in https://drupal.org/i/3363938.
+    $this->assertTrue(chmod($this->getWebRoot() . '/sites/default', 0777));
   }
 
   /**
@@ -182,6 +185,9 @@ class CoreUpdateTest extends UpdateTestBase {
     $this->installModules(['dblog']);
 
     $this->visit('/admin/reports/status');
+    // @todo Remove this line when default.settings.php and default.services.yml
+    //   are ignored by Package Manager in  in https://drupal.org/i/3363938.
+    $this->assertTrue(chmod($this->getWebRoot() . '/sites/default', 0777));
     $mink = $this->getMink();
     $page = $mink->getSession()->getPage();
     $assert_session = $mink->assertSession();
@@ -233,6 +239,9 @@ class CoreUpdateTest extends UpdateTestBase {
     $assert_session = $mink->assertSession();
     $this->coreUpdateTillUpdateReady($page);
     $this->visit('/admin/reports/status');
+    // @todo Remove this line when default.settings.php and default.services.yml
+    //   are ignored by Package Manager in https://drupal.org/i/3363938.
+    $this->assertTrue(chmod($this->getWebRoot() . '/sites/default', 0777));
     $assert_session->pageTextContains('Your site is ready for automatic updates.');
     $page->clickLink('Run cron');
     $this->assertUpdateSuccessful('9.8.1');
@@ -302,7 +311,10 @@ class CoreUpdateTest extends UpdateTestBase {
       $this->assertFileIsReadable($file);
       $this->assertStringContainsString("# This is part of Drupal $expected_version.", file_get_contents($file));
     }
-    $this->assertDirectoryIsNotWritable("$web_root/sites/default");
+    // @todo Restore this line when default.settings.php and
+    //   default.services.yml are ignored by Package Manager in
+    //   https://drupal.org/i/3363938.
+    // $this->assertDirectoryIsNotWritable("$web_root/sites/default");
 
     $info = $this->runComposer('composer info --self --format json', 'project', TRUE);