Rust plugin prevents from building a single package in workspace

[artivis]

What needs to get done

The rust plugin should support building a single (or several) package(s) in a virtual workspace. The cargo build command offers the --package flag to only build a specific package (the flag can be repeated). However it is superseeded by the --workspace flag which effectively instruct to build all packages (not sure if this precedence is a general rule or a positional thing).

Why it needs to get done

While the plugin doesn't explicitely support specifying a package(s), one could abuse the rust_cargo_parameters to stuff e.g. ['--package', 'foo'].
However, the plugin hardcode the --workspace flag and all packages are built regardless of the workaround.

Edit:

Similarly, a workspace definition may contain the default-members entry. It defines the members of a virtual workspace that should be built in case neither --workspace nor --package are specified.
If default-members isn't specified either, the fallback is to build all (--workspace). So the hardcoded flag could probably be removed altogether from the plugin.

Source: The cargo book.