refactor(toolchain)!: postpone eval of install_if_missing in Toolchain::from_local()

Author: rami3l

src/cli/rustup_mode.rs

@@ -1023,7 +1023,7 @@ async fn run(
     install: bool,
 ) -> Result<ExitStatus> {
     let toolchain = toolchain.resolve(&cfg.get_default_host_triple()?)?;
-    let toolchain = Toolchain::from_local(toolchain, install, cfg).await?;
+    let toolchain = Toolchain::from_local(toolchain, || Ok(install), cfg).await?;
     let cmd = toolchain.command(&command[0])?;
     command::run_command_for_dir(cmd, &command[0], &command[1..])
 }

src/config.rs

@@ -746,10 +746,7 @@ impl<'a> Cfg<'a> {
 
     async fn local_toolchain(&self, name: Option<LocalToolchainName>) -> Result<Toolchain<'_>> {
         match name {
-            Some(tc) => {
-                let install_if_missing = self.should_auto_install()?;
-                Toolchain::from_local(tc, install_if_missing, self).await
-            }
+            Some(tc) => Toolchain::from_local(tc, || self.should_auto_install(), self).await,
             None => {
                 let tc = self
                     .maybe_ensure_active_toolchain(None)

src/toolchain.rs

@@ -53,15 +53,15 @@ pub(crate) struct Toolchain<'a> {
 impl<'a> Toolchain<'a> {
     pub(crate) async fn from_local(
         name: LocalToolchainName,
-        install_if_missing: bool,
+        install_if_missing: impl Fn() -> anyhow::Result<bool>,
         cfg: &'a Cfg<'a>,
     ) -> anyhow::Result<Toolchain<'a>> {
         match Self::new(cfg, name) {
             Ok(tc) => Ok(tc),
             Err(RustupError::ToolchainNotInstalled {
                 name: ToolchainName::Official(desc),
                 ..
-            }) if install_if_missing => {
+            }) if install_if_missing()? => {
                 Ok(
                     DistributableToolchain::install(cfg, &desc, &[], &[], cfg.get_profile()?, true)
                         .await?