Steps to reproduce the issue

Add the following code to the extension's xml file:

install
sql
file charset="utf8" driver="mysql"sql/install.sql/file
/sql
/install
uninstall
sql
file charset="utf8" driver="mysql">sql/uninstall.sql</file
/sql
/uninstall
updat>
schemas
sql/updates
/schemas
/update

Expected result

Create the database as Joomla 3 does.

Actual result

Databases are created but the file specified into tags is not launched, so the extension is not installed.
If I remove that code the installation file is launched and everything is installed, but databases are not created.

System information (as much as possible)

Setting Value

PHP Built On Linux joomla-test 3.13.0-95-generic #142-Ubuntu SMP Fri Aug 12 17:05:16 UTC 2016 i686
Database Version 5.7.19-0ubuntu0.16.04.1
Database Collation utf8mb4_unicode_ci
Database Connection Collation utf8_general_ci
PHP Version 7.0.22-0ubuntu0.16.04.1
Web Server Apache/2.4.18 (Ubuntu)
WebServer to PHP Interface apache2handler
Joomla! Version Joomla! 4.0.0 Alpha 2 Development [ Amani ] 19-November-2017 23:59 GMT
User Agent Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0

Additional comments