WITHOUT CHANGES:

$ git diff
<<nothing>>

$ bin/moodle-docker-compose exec webserver vendor/bin/phpunit --filter test_average_number_of_participants
Moodle 4.1dev (Build: 20220707), a23f0bff3e1f386ceeb686e1d7ce28d8735769e0
Php: 7.4.30, oci: 21.0.0.0.0, OS: Linux 5.10.104-linuxkit x86_64
PHPUnit 9.5.13 by Sebastian Bergmann and contributors.

F                                                                   1 / 1 (100%)

Time: 00:00.952, Memory: 292.00 MB

There was 1 failure:

1) core_course\courselib_test::test_average_number_of_participants
Failed asserting that 0.0 matches expected 2.

WITH ONE SPACE CHANGE:

$ git diff
diff --git a/course/lib.php b/course/lib.php
index 37c89ebc3e4..4e01717e522 100644
--- a/course/lib.php
+++ b/course/lib.php
@@ -2509,7 +2509,7 @@ function average_number_of_participants(bool $onlyactive = false, int $lastlogin
     }

     $sql = "SELECT COUNT(*)
-              FROM ($sql) total";
+             FROM ($sql) total";

$ bin/moodle-docker-compose exec webserver vendor/bin/phpunit --filter test_average_number_of_participants
Moodle 4.1dev (Build: 20220707), a23f0bff3e1f386ceeb686e1d7ce28d8735769e0
Php: 7.4.30, oci: 21.0.0.0.0, OS: Linux 5.10.104-linuxkit x86_64
PHPUnit 9.5.13 by Sebastian Bergmann and contributors.

.                                                                   1 / 1 (100%)

Time: 00:00.927, Memory: 292.00 MB

OK (1 test, 17 assertions)