I would like to direct Apache error output to /proc/self/fd/1 in a VirtualHost block, but it continues to output to the file configured in apache2.conf (error.log).

/etc/apache2/apache2.conf:

ErrorLog ${APACHE_LOG_DIR}/error.log

/etc/apache2/sites-enabled/vhost.conf:

<VirtualHost _default_:80>
  DocumentRoot /data/frontend/web/
  RewriteEngine On
  DirectoryIndex index.php

  <Directory /data/frontend/web/>
    Options FollowSymLinks
    AllowOverride All
    Require all granted
  </Directory>

  LogLevel info
  ErrorLog /proc/self/fd/1
  CustomLog /var/log/apache2/access.log combined

</VirtualHost>

<FilesMatch \.php$>
    SetHandler application/x-httpd-php
</FilesMatch>

I tried using a file to troubleshoot (ErrorLog /var/log/apache2/verrors.log) and I see that Apache creates the file verrors.log but it remains empty and the error.log file gets the log messages.

Other configuration in vhost.conf works as expected, even the CustomLog directive.