You also need to set log_errors = On in php.ini.

The problem I ran into was that the error log I had designated was write protected. All my .htaccess settings were correct, PHP just couldn't write to the error log because it had no permissions. This fixed it right up for me:

chmod 777 watermellon-app-errors.log

Obviously, you're going to want to change the .log to whatever file you're using for a log.

In case anyone else is having trouble getting their local development environment to log errors, here's what fixed it for me:

On windows, error_log must be set to the complete path to the log for error_log() to work (error_log = c:apachephp_errors.log). However, if error_log = php_errors.log with no path, php will still be able to log startup errors such as

PHP Startup: Unable to load dynamic library 'extphp_mysqli.dll' - The specified module could not be found

If the error_log directive is set, the file will be used for recording php errors, when it is not set errors will be logged to the Apache log. Take a look at http://us3.php.net/manual/en/errorfunc.configuration.php#ini.error-log.

The error_log file and the directory it's in must be writable by the user that Apache is running under. If the file isn't being created, it's probably due to a permissions issue.

I don't know for sure why Apache would be crashing on you, but I'm guessing it's a permissions issue of some sort.

Check PHP-FPM is not explicitly setting error_log:

Make sure the file /etc/php-fpm.d/www.conf does not contain php_admin_value settings for error_log. Search for the following and comment them out using a semi-colon:

; NOTE: If these are set, ini_set('error_log', 'path') will have no effect 
; inside your php code, and this will be forced to be the value always.
; php_admin_value[error_log] = /var/log/php-fpm/www-error.log
; php_admin_flag[log_errors] = on

Then restart php-fpm:

systemctl restart php-fpm

Check Apache .htaccess files are not setting the error_log value using

php_admin_value settings in apache configuration files cannot be overridden, so make sure you dont have any php_admin_value for the error_log setting in the Apache configuration files. Also check for php_value settings just in case.

PHP Website - How to change configuration settings

I don't understand why, but the error log is now working. Here is what I did. I gave up and commented back out the error_log directive and closed the ini file. I ran the script with the parse error to see of Apache would still crash and I got the PHP error in the log file. This is freaky because the ini file no longer has error_log enabled and my script is not using ini_set().

Does anyone have an explanation for this madness? Also, Apache no longer crashes.

If you are using Fedora, SELinux (enabled by default) will prevent apache / httpd from appending errors to your log file even when your file is specified in php.ini and its containing directory has all permissions allowed.

You can see if this is happening by looking at your system log file in /var/log/messages

The ideal solution is to configure SELinux to allow access on the log file.

The quicker solution is to disable SELinux in /etc/selinux/config by setting SELINUX to disabled.

You'll need to reboot your system after doing this for the change to take effect.

In my case, on a CentOS development server, after a full yum update the permission on /var/log/http was changed to 700 and the user to 'root', so the user 'apache' wasn't able to enter or write into it. It was still able to write into the existing file /var/log/httpd/error.log but it wasn't able to create a new file, as I use date-suffixed log files.
Issuing the command

chown apache /var/log/httpd

solved the problem.

As bradym said, check whether you have write permissions to the directory where you php error log is located for apache user. If you created a log file with written permissions it's not enough, the dir should have them too.

The error_log = "C:phpLogerror.log" was not working for me either. The solution for me was that you shouldn't create the error.log yourself, because PHP will do it for you. See the PHP message board. I'm using PHP 5.2 on a Windows 2008 server

The way it works on my ubuntu (Apache 2.4.7, PHP 5.5.9) is the following:

command line script:

• writes the log into the path pointed by error_log if log_errors = On. Settings in /etc/php5/cli/php.ini;

web request via apache:

• if log_errors = On (/etc/php5/apache2/php.ini), the error appended into the path pointed by ErrorLog apache directive in the virtualhost. If that directive does not exist, the php.ini error_log path is used;


• if log_errors = Off not logs are written anywhere;

As far as I remember, it almost worked this way in most of the linux stacks

This did the trick for me.

setsebool -P httpd_unified 1

Please note, this would be the preferred method below to try first:

semanage fcontext -a -t httpd_sys_rw_content_t 'errorLogNameHere.error.log
restorecon -v 'errorLogNameHere.error.log'

This answer was derived from the logs from executing this command line:

journalctl -xe 

Further information on the system I was running on:
PHP 7.0 and
CentOS 7

Not sure if it's not obvious, but the issue was Apache's configuration to writing files. I did try chmod 777, chmod a+w on the logging directory, but this didn't work for me.

Hope this can help somebody.

Here is my troubleshooting guide to error_log() calls not working.

1. 
   

   Look at your server's configuration to find out where the default error log file is.

   
   
   

   This depends on which server you're using. To get you started, have a look at Apache's ErrorLog option if you're using Apache or Nginx's error_log option if you're using Nginx. Make sure it is set to a file. If you're using a tool like Valet, note that it's using server software like Nginx behind the scenes.

   
   


2. 
   

   Check the permissions of your server's error log file.

   
   
   

   On Unix-like systems, it should be writeable by the correct user and group, and the permissions of the parent directory and all its ancestors need to be correct as well. Use chmod and chown.

   
   


3. 
   

   Check the configuration of PHP in the .ini files.

   
   
   

   Specifically, check for log_errors = On and error_reporting = E_ALL | E_STRICT and error_log = /tmp/example/php_errors.log (see docs for log_errors, error_reporting and error_log configuration settings). To find the .ini file, look at the output of phpinfo();. If error_log is not set, by default it goes to the error log for the server, mentioned in the previous steps. If error_log is set to a file, it should already exist and be writeable, just like in previous steps. Remember to restart the server after configuration changes.

   
   


4. 
   

   Check that PHP's settings aren't being changed by server configuration.

   
   
   

   Your server's configuration (even .htaccess) can change PHP configuration settings. In Apache, this is done using php_admin_value and php_admin_flag (docs). For instance, you may find in your .htaccess file this line: php_admin_flag[log_errors] = off. Remember to restart the server after configuration changes.

   
   
   

   At this point, you should be able to create a test file test.php with the contents <?php error_log("test");, restart your server, and open the URL in your browser, and you should be able to see test in your error log (either the server's, or the one specified by error_log =). But keep reading.

   
   


5. 
   

   Check that PHP's settings aren't being changed at run-time.

   
   
   

   The log_errors option can be changed at runtime by running ini_set('log_errors', 1);, and so can the other configuration options error_reporting and error_log. Also note there is a special error_reporting() PHP function which changes the configuration at run-time. Search your code-base for any invocations of ini_set or error_reporting. WordPress for example does run these depending on the value of WP_DEBUG.

   
   

Other things to look at: You may be having permission issues in SELinux (see this answer).