error duplicate-impl
У сервиса больше одной impl.
What it means#
A service has exactly one impl. A second one (or any impl of an extern service) is rejected.
Example#
service Twice { rpc ping() -> i32 }
impl Twice { rpc ping() { 1 } }
impl Twice { rpc ping() { 2 } } // <- duplicate-implerror
duplicate-impl
How to fix#
Merge the two blocks. An extern service is implemented by another program and has no impl here.