laravel new blog not work mockery/mockery 1.4.0

Run composer update.

The reason:

Your PHP version is too low. You've got 7.2.23 installed, and mockery/mockery 1.4 requires 7.3.0

The best solution is to upgrade your PHP version. Alternatively, you can reduce mockery's version to 1.3.1, which only requires PHP 5.6 or above.

My bug report can be found here

As of 2020-05-21, the zip files that laravel new ___ uses will try to install mockery/mockery version 1.4. This won't work with versions of PHP below 7.3. In order to fix this, run composer update, and mockery will be downgraded to a compatible version.

I had the same problem today for new Laravel projects. The composer.json file was showing "mockery/mockery": "^1.3.1" but still was showing the same error. Delete also the composer.lock file and run composer install.