This script is used to check whether all tools, which are not handled by composer and are needed by one or multiple scripts, are installed.
It uses the src/dependencies.ini file to know which tools are needed how to report them. Whenever a tool is missing and the src/dependencies.ini contains information on how to install that tool for the current OS that information will be reported.
The script is automatically triggered during composers post-update phase, but can also be triggered by hand.
dependencies_check.php