Herd not displaying actual php error. it's showwing 500 error

To diagnose and display the actual PHP error instead of a generic 500 Internal Server Error, you can follow these steps:

1. Enable Error Reporting in PHP: Ensure that PHP is configured to display errors. You can do this by modifying your php.ini file or by adding the following lines at the beginning of your PHP script:

   ini_set('display_errors', 1);
   ini_set('display_startup_errors', 1);
   error_reporting(E_ALL);
   

2. Check Your Web Server Configuration: Sometimes, the web server configuration might be suppressing the error messages. If you are using Apache, make sure that the display_errors directive is set to On in your .htaccess file or in the server configuration:

   php_flag display_errors on
   

   For Nginx with PHP-FPM, ensure that the php.ini file used by PHP-FPM has display_errors enabled.

3. Review Your Error Logs: Check the web server error logs for more detailed information about the error. For Apache, the error log is usually located at /var/log/apache2/error.log, and for Nginx, it is typically at /var/log/nginx/error.log.

4. Use a Custom Error Handler: Implement a custom error handler in your PHP application to catch and display errors more gracefully. Here is an example of a simple custom error handler:

   set_error_handler(function ($errno, $errstr, $errfile, $errline) {
       echo "<b>Error:</b> [$errno] $errstr - $errfile:$errline";
       echo "<br>";
       echo "Terminating PHP script.";
       die();
   });
   
   // Example code that triggers an error
   echo $undefined_variable;
   

5. Check for Fatal Errors: If your script is encountering a fatal error, it might not be displayed due to the script termination. You can use the register_shutdown_function to catch fatal errors:

   register_shutdown_function(function () {
       $error = error_get_last();
       if ($error !== NULL) {
           $info = "[SHUTDOWN] level: {$error['type']}, message: {$error['message']}, file: {$error['file']}, line: {$error['line']}";
           echo $info;
       }
   });
   
   // Example code that triggers a fatal error
   non_existent_function();
   

By following these steps, you should be able to see the actual PHP error messages instead of a generic 500 Internal Server Error. This will help you debug and resolve the issue more effectively.