feat(cli/rustup-mode): add --force-non-host to rustup default

Author: rami3l

src/cli/rustup_mode.rs

@@ -161,6 +161,10 @@ enum RustupSubcmd {
     Default {
         #[arg(help = MAYBE_RESOLVABLE_TOOLCHAIN_ARG_HELP)]
         toolchain: Option<MaybeResolvableToolchainName>,
+
+        /// Install toolchains that require an emulator. See https://github.com/rust-lang/rustup/wiki/Non-host-toolchains
+        #[arg(long)]
+        force_non_host: bool,
     },
 
     /// Modify or query the installed toolchains
@@ -631,7 +635,10 @@ pub async fn main(
             ToolchainSubcmd::Uninstall { opts } => toolchain_remove(cfg, opts),
         },
         RustupSubcmd::Check => check_updates(cfg).await,
-        RustupSubcmd::Default { toolchain } => default_(cfg, toolchain).await,
+        RustupSubcmd::Default {
+            toolchain,
+            force_non_host,
+        } => default_(cfg, toolchain, force_non_host).await,
         RustupSubcmd::Target { subcmd } => match subcmd {
             TargetSubcmd::List {
                 toolchain,
@@ -710,6 +717,7 @@ pub async fn main(
 async fn default_(
     cfg: &Cfg<'_>,
     toolchain: Option<MaybeResolvableToolchainName>,
+    force_non_host: bool,
 ) -> Result<utils::ExitCode> {
     common::warn_if_host_is_emulated(cfg.process);
 
@@ -725,7 +733,7 @@ async fn default_(
             MaybeResolvableToolchainName::Some(ResolvableToolchainName::Official(toolchain)) => {
                 let desc = toolchain.resolve(&cfg.get_default_host_triple()?)?;
                 let status = cfg
-                    .ensure_installed(&desc, vec![], vec![], None, false, true)
+                    .ensure_installed(&desc, vec![], vec![], None, force_non_host, true)
                     .await?
                     .0;
 

tests/suite/cli-ui/rustup/rustup_default_cmd_help_flag_stdout.toml

@@ -4,14 +4,16 @@ stdout = """
 ...
 Set the default toolchain
 
-Usage: rustup[EXE] default [TOOLCHAIN]
+Usage: rustup[EXE] default [OPTIONS] [TOOLCHAIN]
 
 Arguments:
   [TOOLCHAIN]  'none', a toolchain name, such as 'stable', 'nightly', '1.8.0', or a custom toolchain
                name. For more information see `rustup help toolchain`
 
 Options:
-  -h, --help  Print help
+      --force-non-host  Install toolchains that require an emulator. See
+                        https://github.com/rust-lang/rustup/wiki/Non-host-toolchains
+  -h, --help            Print help
 
 Discussion:
     Sets the default toolchain to the one specified. If the toolchain