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

Author: rami3l

src/cli/rustup_mode.rs

@@ -1096,7 +1096,7 @@ async fn run(
     install: bool,
 ) -> Result<ExitStatus> {
     let toolchain = toolchain.resolve(&cfg.default_host_tuple()?)?;
-    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

@@ -717,13 +717,10 @@ impl<'a> Cfg<'a> {
         name: Option<(LocalToolchainName, ActiveSource)>,
     ) -> Result<(Toolchain<'_>, ActiveSource)> {
         match name {
-            Some((tc, source)) => {
-                let install_if_missing = self.should_auto_install()?;
-                Ok((
-                    Toolchain::from_local(tc, install_if_missing, self).await?,
-                    source,
-                ))
-            }
+            Some((tc, src)) => Ok((
+                Toolchain::from_local(tc, || self.should_auto_install(), self).await?,
+                src,
+            )),
             None => {
                 let (tc, source) = self
                     .maybe_ensure_active_toolchain(None)

src/toolchain.rs

@@ -52,15 +52,15 @@ 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()? => {
                 let options = DistOptions::new(&[], &[], &desc, cfg.get_profile()?, true, cfg)?;
                 Ok(DistributableToolchain::install(options).await?.1.toolchain)
             }