message: check whether correct target arg passed in
diff: @@ -88,7 +88,7 @@ pub struct BuildOptions {
  pub scope: Option<String>,
  #[structopt(long = "mode", short = "m", default_value = "normal")]
  - /// Sets steps to be run. [possible values: no-install, normal]
  + /// Sets steps to be run. [possible values: no-install, normal, force]
  pub mode: BuildMode,
  #[structopt(long = "no-typescript")]
  @@ -158,6 +158,12 @@ impl Build {
  _ => bail!("Can only supply one of the --dev, --release, or --profiling flags"),
  };
  + // `possible_values` in clap isn't supported by `structopt`
  + let possible_targets = ["browser", "nodejs", "no-modules"];
  + if !possible_targets.contains(&build_opts.target.as_str()) {
  + bail!("Supported targets: browser, nodejs, no-modules");
  + }
  +
  Ok(Build {
  crate_path,
  crate_data,
  