Add config option for Elan self-update

src/config.rs

@@ -377,6 +377,12 @@ pub struct Composer {
     self_update: Option<bool>,
 }
 
+#[derive(Deserialize, Default, Debug, Merge)]
+#[serde(deny_unknown_fields)]
+pub struct Elan {
+    self_update: Option<bool>,
+}
+
 #[derive(Deserialize, Default, Debug, Merge)]
 #[serde(deny_unknown_fields)]
 pub struct Vim {
@@ -509,6 +515,9 @@ pub struct ConfigFile {
     #[merge(strategy = crate::utils::merge_strategies::inner_merge_opt)]
     deno: Option<Deno>,
 
+    #[merge(strategy = crate::utils::merge_strategies::inner_merge_opt)]
+    elan: Option<Elan>,
+
     #[merge(strategy = crate::utils::merge_strategies::inner_merge_opt)]
     vim: Option<Vim>,
 
@@ -1245,6 +1254,15 @@ impl Config {
             .unwrap_or(false)
     }
 
+    /// Whether Elan should update itself
+    pub fn elan_self_update(&self) -> bool {
+        self.config_file
+            .elan
+            .as_ref()
+            .and_then(|c| c.self_update)
+            .unwrap_or(true)
+    }
+
     /// Whether to force plug update in Vim
     pub fn force_vim_plug_update(&self) -> bool {
         self.config_file

src/steps/generic.rs

@@ -258,10 +258,12 @@ pub fn run_elan(ctx: &ExecutionContext) -> Result<()> {
     let elan = require("elan")?;
 
     print_separator("elan");
-    ctx.run_type()
-        .execute(&elan)
-        .args(["self", "update"])
-        .status_checked()?;
+    if ctx.config().elan_self_update() {
+        ctx.run_type()
+           .execute(&elan)
+           .args(["self", "update"])
+           .status_checked()?;
+    }
     ctx.run_type().execute(&elan).arg("update").status_checked()
 }