uninstalls toolchains prior to deleting the rustup home folder

src/cli/rustup_mode.rs

@@ -812,7 +812,7 @@ pub async fn main(
             SelfSubcmd::Uninstall {
                 no_prompt,
                 no_modify_path,
-            } => self_update::uninstall(no_prompt, no_modify_path, process),
+            } => self_update::uninstall(no_prompt, no_modify_path, cfg),
             SelfSubcmd::UpgradeData => cfg.upgrade_data().map(|_| ExitCode::SUCCESS),
         },
         RustupSubcmd::Set { subcmd } => match subcmd {

src/cli/self_update.rs

@@ -1049,23 +1049,21 @@ async fn maybe_install_rust(opts: InstallOpts<'_>, cfg: &mut Cfg<'_>) -> Result<
 }
 
 /// Uninstall process:
-/// 1. Remove rustup home.
-/// 2. Remove all entries in `$CARGO_HOME` except `bin`.
-/// 3. Remove rustup tool links and binary.
-/// 4. Try to remove $CARGO_HOME/bin directory if it's empty.
-/// 5. Upon successfully removing $CARGO_HOME/bin, clean up $PATH.
-/// 6. Try to remove $CARGO_HOME directory if it's empty.
-pub(crate) fn uninstall(
-    no_prompt: bool,
-    no_modify_path: bool,
-    process: &Process,
-) -> Result<ExitCode> {
+/// 1. Remove all installed toolchains.
+/// 2. Remove rustup home.
+/// 3. Remove all entries in `$CARGO_HOME` except `bin`.
+/// 4. Remove rustup tool links and binary.
+/// 5. Try to remove $CARGO_HOME/bin directory if it's empty.
+/// 6. Upon successfully removing $CARGO_HOME/bin, clean up $PATH.
+/// 7. Try to remove $CARGO_HOME directory if it's empty.
+pub(crate) fn uninstall(no_prompt: bool, no_modify_path: bool, cfg: &Cfg<'_>) -> Result<ExitCode> {
     if cfg!(feature = "no-self-update") {
         error!("self-uninstall is disabled for this build of rustup");
         error!("you should probably use your system package manager to uninstall rustup");
         return Ok(ExitCode::FAILURE);
     }
 
+    let process = cfg.process;
     let cargo_home = process.cargo_home()?;
 
     if !cargo_home.join(format!("bin/rustup{EXE_SUFFIX}")).exists() {
@@ -1089,6 +1087,11 @@ pub(crate) fn uninstall(
         }
     }
 
+    info!("removing toolchains");
+    for toolchain in cfg.list_toolchains()? {
+        Toolchain::ensure_removed(cfg, toolchain.into())?;
+    }
+
     info!("removing rustup home");
 
     // Delete RUSTUP_HOME

tests/suite/cli_self_upd.rs

@@ -205,6 +205,28 @@ async fn uninstall_deletes_bins() {
     assert!(!rust_gdbgui.exists());
 }
 
+#[tokio::test]
+async fn uninstall_deletes_installed_toolchains() {
+    let cx = setup_empty_installed().await;
+    let path = cx.config.customdir.join("custom-1");
+    let path = path.to_string_lossy();
+    cx.config
+        .expect(["rustup", "toolchain", "link", "custom", &path])
+        .await
+        .is_ok();
+    cx.config
+        .expect(["rustup", "self", "uninstall", "-y"])
+        .await
+        .with_stderr(snapbox::str![[r#"
+...
+info: uninstalling toolchain custom
+info: toolchain custom uninstalled
+...
+"#]])
+        .is_ok();
+    assert!(!cx.config.rustupdir.join("toolchains").exists());
+}
+
 #[tokio::test]
 async fn uninstall_works_if_some_bins_dont_exist() {
     let cx = setup_empty_installed().await;