What are the best practices for installing and enabling PHP modules in a situation where the required modules are no longer available in repositories?

When required PHP modules are no longer available in repositories, one solution is to manually install the modules by downloading the source code, compiling it, and enabling it in the PHP configuration file. This process may involve downloading the source code, compiling it with the appropriate flags, and then adding the module to the PHP configuration file to enable it.

// Example PHP code snippet to manually install and enable a PHP module
// Download the source code for the module
// Compile the module with appropriate flags
// Add the module to the PHP configuration file to enable it