Fixes #3994: Get environment detector subclass results on bootstrap. (#…

…4017)

src/Robo/Common/EnvironmentDetector.php

@@ -332,6 +332,31 @@ public static function getAcsfDbName() {
     return isset($GLOBALS['gardens_site_settings']) && self::isAcsfEnv() ? $GLOBALS['gardens_site_settings']['conf']['acsf_db_name'] : NULL;
   }
 
+  /**
+   * Find the repo root.
+   *
+   * This isn't as trivial as it sounds, since a simple relative path
+   * (__DIR__ . '/../../../../../../') won't work if this package is symlinked
+   * using a Composer path repository, and this file can be invoked from both
+   * web requests and BLT CLI calls.
+   *
+   * @return string
+   *   The repo root as an absolute path.
+   */
+  public static function getRepoRoot() {
+    if (defined('DRUPAL_ROOT')) {
+      // This is a web or Drush request.
+      return DRUPAL_ROOT . '/..';
+    }
+    else {
+      // This is a BLT CLI call. Get the $repo_root that was set in
+      // bin/blt-robo.php.
+      // phpcs:ignore
+      global $repo_root;
+      return $repo_root;
+    }
+  }
+
   /**
    * Call a given function in all EnvironmentDetector subclasses.
    *
@@ -348,11 +373,7 @@ public static function getAcsfDbName() {
    * @throws \ReflectionException
    */
   private static function getSubclassResults($functionName) {
-    if (!defined('DRUPAL_ROOT')) {
-      // Do nothing if called outside of a Drupal bootstrap.
-      return [];
-    }
-    $autoloader = require DRUPAL_ROOT . '/autoload.php';
+    $autoloader = require self::getRepoRoot() . '/vendor/autoload.php';
     $classMap = $autoloader->getClassMap();
     $detectors = array_filter($classMap, function ($classPath) {
       return strpos($classPath, 'Blt/Plugin/EnvironmentDetector') !== FALSE;