cURL error 6: Could not resolve host:


I’m having the reported error in nextcloud log file.
Software is nc18.0.4, Hardware Rpi4 (ARM)

I see a lot of these errors. Is it possible to see the CURL activities?
I tried modifying CurlHandler.php
Adding: ob_start() CURLOPT_{VERBOSE,STDERR}, … fclose(); $v = ob_get_clean()
Result $v has 0 len.
Expected Result: " `* About to connect() to"
Note: /var/log/apache2/error.log contains rows like “Expire in 10000 ms for 8” but its doesn’t seem to contain verbose information (e.g. request payload, port, …)

Next step is start capturing packets with wireshark.
Have you other hints about this topic?

Thanks for your attention
I started by trying to keep sd read-only (


I’ve identified the problem, perhaps not related to NC.
Only when requesting php from apache2 multi-instance, the dns is asked to a non-existent dns server. This does not happen when the php is called with php command or when apache2 is started in debug mode (-X).

I attached the evidences for anyone interested.