0 - Prerequisites Ensure that there is NOT any $CFG->moodledata/environment directory in your installation. If it exists... it contains old environment info. Remove the directory completely before continuing with the tests below. A - On Master, 401, 400, 311 and 39 (all supported and security supported branches): Note: This needs to be tested on all the databases that are affected by the changes (Check the databases mentioned on the list) Go to admin -> server -> environment One "4.2 upwards" Moodle version should be available. VERIFY that It shows the same requirements as the 4.1 version but with these differences: PHP 8.0 is required (instead of 7.4). Moodle 3.11.8 is required (instead of 3.9) Databases MySQL 8.0 is required (instead of 5.7). MariaDB 10.6.7 is required (instead of 10.4) PostgreSQL 13 is required (instead of 12). The php-sodium extension is now required (previously recommended). 64 bits are now required (previously recommended). Note that this check doesn't appear unless your host is 32 bits, so it's also ok if this check isn't shown, we'll test it later. B - Verify, for all the numeric (XYZ) branches above, that the environment.xml file is 100% the same (requires git or diff use). All the commands should return NO differences (nothing should be output): Note: It's enough to test on one instance only (e.g. on a master instance) git diff MOODLE_XYZ_STABLE master admin/environment.xml C - Upgrade tests (easier with MDK): Note: Test on master only. No need to test on the other branches. C-1 Using minimum supported version Install Moodle 3.11.8 Uninstall your current instance mdk uninstall -y Checkout the 3.11.8 tag git checkout v3.11.8 Install mdk install Add some courses and one activity or two mdk run makecourse Attempt upgrade to master Checkout the master branch. git checkout master Upgrade either via the browser or via CLI ( mdk upgrade ) VERIFY : that upgrade works C-2 Using older, non-supported version Install Moodle 3.11.7 Uninstall your current instance mdk uninstall -y Checkout the 3.11.7 tag git checkout v3.11.7 Install mdk install Add some courses and one activity or two mdk run makecourse Attempt upgrade to master Checkout the master branch. git checkout master Open the moodle instance on your browser VERIFY : that upgrade is blocked D - Check that the 64 bits new requirements is working Note: because it's really hard to find a 32 bits environment, we are going to hack in existing code to simulate that our environment is that way. Install Moodle 4.2dev (master) Uninstall your current instance mdk uninstall -y Checkout the master branch git checkout master Install mdk install Go to the site Admin -> Server -> Environment page Verify that there isn't any "php not 64 bits" warning or error (that means that your system is 64bits). Edit the lib/upgradelib.php file. In the check_sixtyfour_bits function, apply this change (replace the "4" with "8"): - if (PHP_INT_SIZE === 4) { + if (PHP_INT_SIZE === 8) { Reload the Admin -> Server -> Environment page Verify the there is a "php not 64 bits" error (red) in the "Other checks" section. With the link "this test must pass" and a brief explanation with the text "It has been detected that your site is not...". The status column shows a "Check" pill, also in red. Verify that the "this test must pass link" sends you to a page in the (401) docs with a note that says: "Note: Since Moodle 4.2 it's required to use a 64-bit version of PHP and the underlying Operating System." Uninstall your current instance mdk uninstall -y Install again (without any git operation, so the hack applied above is still present). mdk install Verify that installation is blocked. Undo the change that was applied above (replace the "8" with the original "4"): Install again mdk install Verify that the installation happens without problem.