From 39e8e91235769e9ba7a979a3f9c5dc36e82fab0c Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Sun, 21 May 2023 16:42:47 +0100
Subject: [PATCH] Default host: aarch64-apple-darwin rustup home: 
 /Users/johnk/.rustup

installed toolchains
--------------------

stable-aarch64-apple-darwin (default)
nightly-2023-04-23-aarch64-apple-darwin
nightly-aarch64-apple-darwin
1.60-aarch64-apple-darwin
1.69-aarch64-apple-darwin
dev
stage1
stage2
1.65.0-aarch64-apple-darwin
1.69.0-aarch64-apple-darwin

installed targets for active toolchain
--------------------------------------

aarch64-apple-darwin
aarch64-pc-windows-msvc
wasm32-unknown-unknown

active toolchain
----------------

stable-aarch64-apple-darwin (default)
rustc 1.69.0 (84c898d65 2023-04-16) shouldn't install things
---
 src/cli/rustup_mode.rs |  4 ++--
 src/config.rs          | 22 ++++++++++++++++++++--
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/cli/rustup_mode.rs b/src/cli/rustup_mode.rs
index 56d3c5c0cd..8097179584 100644
--- a/src/cli/rustup_mode.rs
+++ b/src/cli/rustup_mode.rs
@@ -1069,8 +1069,8 @@ fn show(cfg: &Cfg, m: &ArgMatches) -> Result<utils::ExitCode> {
 
     let cwd = utils::current_dir()?;
     let installed_toolchains = cfg.list_toolchains()?;
-    // XXX: we may want a find_without_install capability for show.
-    let active_toolchain = cfg.find_or_install_override_toolchain_or_default(&cwd);
+    // Retrieve the active toolchain but do not install it
+    let active_toolchain = cfg.find_override_toolchain_or_default(&cwd);
 
     // active_toolchain will carry the reason we don't have one in its detail.
     let active_targets = if let Ok(ref at) = active_toolchain {
diff --git a/src/config.rs b/src/config.rs
index 3e1fbcd8a1..b0d9e7016d 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -659,6 +659,22 @@ impl Cfg {
     pub(crate) fn find_or_install_override_toolchain_or_default(
         &self,
         path: &Path,
+    ) -> Result<(Toolchain<'_>, Option<OverrideReason>)> {
+        self.find_toolchain(path, true)
+    }
+
+    #[cfg_attr(feature = "otel", tracing::instrument(skip_all))]
+    pub(crate) fn find_override_toolchain_or_default(
+        &self,
+        path: &Path,
+    ) -> Result<(Toolchain<'_>, Option<OverrideReason>)> {
+        self.find_toolchain(path, false)
+    }
+
+    fn find_toolchain(
+        &self,
+        path: &Path,
+        install_if_missing: bool,
     ) -> Result<(Toolchain<'_>, Option<OverrideReason>)> {
         let (toolchain, components, targets, reason, profile) =
             match self.find_override_config(path)? {
@@ -688,7 +704,7 @@ impl Cfg {
                 let components: Vec<_> = components.iter().map(AsRef::as_ref).collect();
                 let targets: Vec<_> = targets.iter().map(AsRef::as_ref).collect();
                 let toolchain = match DistributableToolchain::new(self, desc.clone()) {
-                    Err(RustupError::ToolchainNotInstalled(_)) => {
+                    Err(RustupError::ToolchainNotInstalled(_)) if install_if_missing => {
                         DistributableToolchain::install(
                             self,
                             &desc,
@@ -700,7 +716,9 @@ impl Cfg {
                         .1
                     }
                     Ok(mut distributable) => {
-                        if !distributable.components_exist(&components, &targets)? {
+                        if install_if_missing
+                            && !distributable.components_exist(&components, &targets)?
+                        {
                             distributable.update(
                                 &components,
                                 &targets,