As a warning for all... It seems that version 1.10.3-1+deb9u1~bpo8+1 wasn't tested before upload. Despite a changelog entry: * Build against openssl 1.0.2 enabling ALPN support for http/2. it looks like it wasn't built on jessie, and ended up with an unsatisfiable dependency on libssl1.1. -- Steve McIntyre, Cambridge, UK. steve@einval.com Welcome my son, welcome to the machine.