Issue #20198 has been reported by kjtsanaktsidis (KJ Tsanaktsidis). ---------------------------------------- Bug #20198: Threaded DNS resolver does not propagate errno to the calling thread https://bugs.ruby-lang.org/issues/20198 * Author: kjtsanaktsidis (KJ Tsanaktsidis) * Status: Open * Priority: Normal * Assignee: kjtsanaktsidis (KJ Tsanaktsidis) * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- If we get a return value of `EAI_SYSTEM` from `getaddrinfo`, we transform that into an appropriate `Errno::` exception on the Ruby side. However, because we now run the actual call to `getaddrinfo` in a thread, we lose that `errno` value (because `errno` is thread-local). So, what we actually raise in case of `EAI_SYSTEM` is just the last error which happened on the calling thread - e.g. this `ECHILD` which presumably got set in the bowels of pthreads somewhere: ``` 1) Socket::IPSocket#getaddress raises an error on unknown hostnames ERROR Expected SocketError but got: Errno::ECHILD (No child processes - getaddrinfo) /home/runner/work/ruby/ruby/src/spec/ruby/library/socket/ipsocket/getaddress_spec.rb:22:in `getaddress' /home/runner/work/ruby/ruby/src/spec/ruby/library/socket/ipsocket/getaddress_spec.rb:22:in `block (3 levels) in <top (required)>' /home/runner/work/ruby/ruby/src/spec/ruby/library/socket/ipsocket/getaddress_spec.rb:21:in `block (2 levels) in <top (required)>' /home/runner/work/ruby/ruby/src/spec/ruby/library/socket/ipsocket/getaddress_spec.rb:4:in `<top (required)>' ``` -- https://bugs.ruby-lang.org/