Override default version when using derive macros

[mdirkse]

Hi,

I'm using the derive macro's of clap 3 with a struct, and I want to be able to customize the version string that is used with the auto-generated --version switch.

If you're using the App::new approach you can simply call the .version() function, but how do you do this with derive macros? I know that you can add a #[clap(version)] to the struct def to add the version, but I also want to add a custom string that is determined at runtime (well, compile time really, but runtime for all intents and purposes).

Regards,
Maarten

[CreepySkeleton]

#[clap(version = "...")]. "..." can be any expression of type &'static str

[mdirkse]

Ah right, thanks, I ended up with this:

lazy_static! {
    static ref VERSION: String = format!(
        "{} {}",
        String::from(option_env!("CARGO_PKG_VERSION").unwrap_or("dev")),
        String::from(option_env!("SHA8").unwrap_or("workspace"))
    );
}

#[derive(Clap, Debug)]
#[clap(version = VERSION.as_str())]
struct Args {
   ...