Thank you.

It is for sure a DNS related issue, as strace and the proper use of verbose debugging (ineffective in the buggy debug code that I have posted) show.

I am suspecting that there is an issue with Curl.xs and AsyncDNS, and that Curl.xs (v. 0.56) does _not_ provide a way to set CURLOPT_RESOLVER_START_FUNCTION, which might be necessary for and is available in the underlying libcurl (v. 8.5.0).

I've emailed a question to the maintainer of Net::Curl::Multi, maybe he'll answer.

Hope so, as I am not at all comfortable with the .xs stuff.

I'm curious and have NO IDEA how I could find out which exactly the missing callback is.