feat(rustup): add rustup.channels config (#1206)

config.example.toml

@@ -376,3 +376,8 @@
 # during the pixi step
 # (default: false)
 # include_release_notes = false
+
+[rustup]
+# If set, updates only these channels.
+# (default: [] (all channels))
+# channels = ["stable"]

src/config.rs

@@ -389,6 +389,12 @@ pub struct VscodeConfig {
     profile: Option<String>,
 }
 
+#[derive(Deserialize, Default, Debug, Merge)]
+#[serde(deny_unknown_fields)]
+pub struct Rustup {
+    channels: Option<Vec<String>>,
+}
+
 #[derive(Deserialize, Default, Debug, Merge)]
 #[serde(deny_unknown_fields)]
 /// Configuration file
@@ -473,6 +479,9 @@ pub struct ConfigFile {
 
     #[merge(strategy = crate::utils::merge_strategies::inner_merge_opt)]
     vscode: Option<VscodeConfig>,
+
+    #[merge(strategy = crate::utils::merge_strategies::inner_merge_opt)]
+    rustup: Option<Rustup>,
 }
 
 fn config_directory() -> PathBuf {
@@ -1493,6 +1502,14 @@ impl Config {
                 .unwrap_or(true)
     }
 
+    pub fn rustup_channels(&self) -> Vec<String> {
+        self.config_file
+            .rustup
+            .as_ref()
+            .and_then(|rustup| rustup.channels.clone())
+            .unwrap_or_default()
+    }
+
     pub fn verbose(&self) -> bool {
         self.opt.verbose
     }

src/steps/generic.rs

@@ -262,7 +262,11 @@ pub fn run_rustup(ctx: &ExecutionContext) -> Result<()> {
     let rustup = require("rustup")?;
 
     print_separator("rustup");
-    ctx.execute(rustup).arg("update").status_checked()
+
+    ctx.execute(rustup)
+        .arg("update")
+        .args(ctx.config().rustup_channels())
+        .status_checked()
 }
 
 pub fn run_rye(ctx: &ExecutionContext) -> Result<()> {