Okay, it looks like issues have been created upstream (https://dev.gnupg.org/T3065#111023). But it appears that the gpg devs don't really get how to implement a standards compliant HTTP client:
> Note that an HTTP proxy is independent of the DNS resolver because it works at the HTTP layer. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1788190 Title: gnupg2 not honoring http-proxy argument To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnupg2/+bug/1788190/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs