While testing my patch for #1189 I discovered a related problem which is pre-existing: I can reproduce it on the current git master. For test 1084, even though the exit code is correct (45, CURLE_INTERFACE_FAILED) the error text is wrong and confusing:
src/curl --interface DoesNotExist.example.com http://www.google.com/
curl: (45) Could not resolve host: www.google.com (Domain name not found)
Actually it failed to resolve DoesNotExist.example.com, not www.google.com like the error message says. If you use --proxy then the error message says "Could not resolve proxy" which is also not true.
I am not sure what the best way to fix this would be (I can think of a hack or two), but I just wanted to document it single I noticed it.