does not work via https

[ghost]

unpacked http://cgiirc.org/releases/cgiirc-0.5.12.tar.gz in /usr/local, renamed it to cgiirc

apache2 configuration

<VirtualHost *:443>
    <Directory "/usr/local/cgiirc">
        Options All
        AllowOverride All
        Require all granted
    </Directory>
    Alias /cgi-bin/images /usr/local/cgiirc/images
    ScriptAlias /cgi-bin /usr/local/cgiirc
    ServerAdmin [email protected]
    DocumentRoot /var/www/htdocs.chat.knageroe.nl
    ServerName chat.knageroe.nl
    CustomLog /var/log/apache2/chat.knageroe.nl_access_log combined
    ErrorLog /var/log/apache2/chat.knageroe.nl_error_log

Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateFile /etc/letsencrypt/live/chat.knageroe.nl/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/chat.knageroe.nl/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>

This results in:

An error occurred: Communication socket already exists

I verified that no cgi* files were under /tmp (none at all in fact).