MythRokuPlayer only shows "Retrieving". Logs show "Call to undefined function mysql_connect()"

[bruceleerabbit]

I'm in the common situation where the client is frozen on a page that simply says "Retrieving". When I probe into it, the underlying cause of this differs from what others experience. For example, having no *.mp4 files in the db is known to cause this, but in my case I've ensured that there is an mp4 file. This appears in /var/log/apache2:

[php7:error] [pid 9062] [client 192.168.2.4:57837] PHP Fatal error:  Uncaught Error: Call to undefined function mysql_connect() in /usr/share/mythtv/mythweb/mythroku/xml_data.php:32\nStack trace:\n#0 /usr/share/mythtv/mythweb/mythroku/mythtv_xml.php(3): get_xml_data()\n#1 {main}\n  thrown in /usr/share/mythtv/mythweb/mythroku/xml_data.php on line 32

If I point a browser to the server at http://192.168.2.5/mythweb/mythroku/mythtv_xml.php?type=rec, the output is:

Fatal error: Uncaught Error: Call to undefined function mysql_connect() in /usr/share/mythtv/mythweb/mythroku/xml_data.php:32 Stack trace: #0 /usr/share/mythtv/mythweb/mythroku/mythtv_xml.php(3): get_xml_data() #1 {main} thrown in /usr/share/mythtv/mythweb/mythroku/xml_data.php on line 32