feat(cli): warn when removing the default/active toolchain

src/cli/rustup_mode.rs

@@ -1281,8 +1281,25 @@ async fn toolchain_link(
 }
 
 fn toolchain_remove(cfg: &mut Cfg<'_>, opts: UninstallOpts) -> Result<utils::ExitCode> {
+ let default_toolchain = cfg.get_default().ok().flatten();
+ let active_toolchain = cfg.find_active_toolchain().ok().flatten().map(|(it, _)| it);
+
  for toolchain_name in &opts.toolchain {
  let toolchain_name = toolchain_name.resolve(&cfg.get_default_host_triple()?)?;
+
+ if active_toolchain
+ .as_ref()
+ .is_some_and(|n| n == &toolchain_name)
+ {
+ warn!("removing the active toolchain; a toolchain override will be required for running Rust tools");
+ }
+ if default_toolchain
+ .as_ref()
+ .is_some_and(|n| n == &toolchain_name)
+ {
+ warn!("removing the default toolchain; proc-macros and build scripts might no longer build");
+ }
+
  Toolchain::ensure_removed(cfg, (&toolchain_name).into())?;
  }
  Ok(utils::ExitCode(0))

src/toolchain/names.rs

@@ -359,6 +359,15 @@ from_variant!(
  LocalToolchainName::Path
 );
 
+impl PartialEq<ToolchainName> for LocalToolchainName {
+ fn eq(&self, other: &ToolchainName) -> bool {
+ match self {
+ LocalToolchainName::Named(n) => n == other,
+ _ => false,
+ }
+ }
+}
+
 impl Display for LocalToolchainName {
  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
  match self {

tests/suite/cli_v2.rs

@@ -212,18 +212,39 @@ async fn list_toolchains_with_none() {
 }
 
 #[tokio::test]
-async fn remove_toolchain() {
+async fn remove_toolchain_default() {
  let mut cx = CliTestContext::new(Scenario::SimpleV2).await;
  cx.config.expect_ok(&["rustup", "update", "nightly"]).await;
  cx.config
- .expect_ok(&["rustup", "toolchain", "remove", "nightly"])
+ .expect_stderr_ok(
+ &["rustup", "toolchain", "remove", "nightly"],
+ "removing the default toolchain; proc-macros and build scripts might no longer build",
+ )
  .await;
  cx.config.expect_ok(&["rustup", "toolchain", "list"]).await;
  cx.config
  .expect_stdout_ok(&["rustup", "toolchain", "list"], "no installed toolchains")
  .await;
 }
 
+#[tokio::test]
+async fn remove_toolchain_active() {
+ let mut cx = CliTestContext::new(Scenario::SimpleV2).await;
+ cx.config.expect_ok(&["rustup", "default", "nightly"]).await;
+ cx.config
+ .expect_ok(&["rustup", "override", "set", "stable"])
+ .await;
+ cx.config
+ .expect_stderr_ok(
+ &["rustup", "toolchain", "remove", "stable"],
+ "removing the active toolchain; a toolchain override will be required for running Rust tools",
+ )
+ .await;
+ cx.config
+ .expect_stdout_ok(&["rustup", "toolchain", "list"], "nightly")
+ .await;
+}
+
 // Issue #2873
 #[tokio::test]
 async fn remove_toolchain_ignore_trailing_slash() {