There were 33 warnings:

1) core_adhoc_task_testcase::test_get_concurrency_limit
"@covers \core\task\adhoc_test::get_concurrency_limit" is invalid

2) core_adhoc_task_testcase::test_get_concurrency_limit_default
"@covers \core\task\adhoc_test::get_concurrency_limit" is invalid

3) core_adhoc_task_testcase::test_get_concurrency_limit_for_task
"@covers \core\task\adhoc_test::get_concurrency_limit" is invalid

4) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "Google" ('google', '.well-known/openid-configuration')
"@covers ::create_endpoints_for_standard_issuer" is invalid

5) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "Google will work too with a valid baseurl parameter" ('google', '.well-known/openid-configuration', true, 'https://accounts.google.com/')
"@covers ::create_endpoints_for_standard_issuer" is invalid

6) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "IMS OBv2.1" ('imsobv2p1', '.well-known/badgeconnect.json', false, 'https://dc.imsglobal.org/')
"@covers ::create_endpoints_for_standard_issuer" is invalid

7) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "IMS OBv2.1 without slash in baseurl should work too" ('imsobv2p1', '.well-known/badgeconnect.json', false, 'https://dc.imsglobal.org')
"@covers ::create_endpoints_for_standard_issuer" is invalid

8) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "IMS OBv2.1 with empty baseurl should return an exception" ('imsobv2p1', null, false, null, 'moodle_exception')
"@covers ::create_endpoints_for_standard_issuer" is invalid

9) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "Microsoft" ('microsoft')
"@covers ::create_endpoints_for_standard_issuer" is invalid

10) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "Facebook" ('facebook')
"@covers ::create_endpoints_for_standard_issuer" is invalid

11) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "NextCloud" ('nextcloud', null, true, 'https://dummy.local/nextcloud/')
"@covers ::create_endpoints_for_standard_issuer" is invalid

12) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "NextCloud with empty baseurl should return an exception" ('nextcloud', null, true, null, 'moodle_exception')
"@covers ::create_endpoints_for_standard_issuer" is invalid

13) core_oauth2_testcase::test_create_endpoints_for_standard_issuer with data set "Invalid type should return an exception" ('fictitious', null, true, null, 'moodle_exception')
"@covers ::create_endpoints_for_standard_issuer" is invalid

14) core\output\mustache_clean_string_helper_test::test_cleanstr
"@covers \mustache_clean_string_helper::cleanstr" is invalid

15) tool_admin_presets\helper_test::test_create_preset
"@covers \helper::create_preset" is invalid

16) tool_admin_presets\helper_test::test_create_preset with data set "Name not empty" ('Preset xaxi name')
"@covers \helper::create_preset" is invalid

17) tool_admin_presets\helper_test::test_create_preset with data set "Comments not empty" (null, 'This is a different comment')
"@covers \helper::create_preset" is invalid

18) tool_admin_presets\helper_test::test_create_preset with data set "Name and comments not empty" ('Preset with a super-nice name', 'This is a comment different f...us one')
"@covers \helper::create_preset" is invalid

19) tool_admin_presets\helper_test::test_add_item with data set "Setting without plugin" ('settingname', 'thisisthevalue')
"@covers \helper::add_item" is invalid

20) tool_admin_presets\helper_test::test_add_item with data set "Setting with plugin" ('settingname', 'thisisthevalue', 'pluginname')
"@covers \helper::add_item" is invalid

21) tool_admin_presets\helper_test::test_add_item with data set "Setting with advanced item" ('settingname', 'thevalue', 'pluginname', 'advsettingname', 'advsettingvalue')
"@covers \helper::add_item" is invalid

22) tool_admin_presets\helper_test::test_add_plugin with data set "Plugin: enabled (using int)" ('plugintype', 'pluginname', 1)
"@covers \helper::add_plugin" is invalid

23) tool_admin_presets\helper_test::test_add_plugin with data set "Plugin: enabled (using bool)" ('plugintype', 'pluginname', true)
"@covers \helper::add_plugin" is invalid

24) tool_admin_presets\helper_test::test_add_plugin with data set "Plugin: disabled (using int)" ('plugintype', 'pluginname', 0)
"@covers \helper::add_plugin" is invalid

25) tool_admin_presets\helper_test::test_add_plugin with data set "Plugin: disabled (using bool)" ('plugintype', 'pluginname', false)
"@covers \helper::add_plugin" is invalid

26) tool_admin_presets\helper_test::test_add_plugin with data set "Plugin: negative int value" ('plugintype', 'pluginname', -9999)
"@covers \helper::add_plugin" is invalid

27) tool_admin_presets\helper_test::test_change_default_preset with data set "Starter preset" ('starter', array(0, 0), array(1, 0, 0, 0))
"@covers \helper::change_default_preset" is invalid

28) tool_admin_presets\helper_test::test_change_default_preset with data set "Full preset" ('full', array(1, 0), array(1, 1, 1, 1))
"@covers \helper::change_default_preset" is invalid

29) tool_admin_presets\helper_test::test_change_default_preset with data set "Preset 1, created manually" ('Preset 1', array(0, 1), array(1, 0))
"@covers \helper::change_default_preset" is invalid

30) tool_admin_presets\helper_test::test_change_default_preset with data set "Unexisting preset name" ('unexisting')
"@covers \helper::change_default_preset" is invalid

31) tool_admin_presets\helper_test::test_change_default_preset with data set "Valid XML file" ('/Users/stronk7/git_moodle/tes...ns.xml', array(1, 1), array(1, 0, 0, 1))
"@covers \helper::change_default_preset" is invalid

32) tool_admin_presets\helper_test::test_change_default_preset with data set "Invalid XML file" ('/Users/stronk7/git_moodle/tes...le.xml')
"@covers \helper::change_default_preset" is invalid

33) tool_admin_presets\helper_test::test_change_default_preset with data set "Unexisting XML file" ('/Users/stronk7/git_moodle/tes...ng.xml')
"@covers \helper::change_default_preset" is invalid