Build ignores RUSTFLAGS
Created by: athei
cargo contract build
ignores flags passed in through the RUSTFLAGS
environment variable. Variables passed in through the cargo config are also ignored. The reason is likely that they are overridden here:
https://github.com/paritytech/cargo-contract/blob/f8f048fbace9c10bb414fb4da0df91df772a12d8/src/cmd/build.rs#L57-L61
They should be merged with the pre-existing options where pre-existing options take precedence in case of conflicts.
Likely a similar change is necessary for metadata generation.