test(cli): ensure the resolution of #3737

tests/suite/cli_misc.rs

@@ -713,6 +713,45 @@ info: toolchain 'test' uninstalled
     });
 }
 
+// issue #3737
+#[test]
+#[cfg(any(unix, windows))]
+fn toolchain_symlink() {
+    use rustup::utils::raw::symlink_dir;
+    use std::fs;
+
+    clitools::test(Scenario::SimpleV2, &|config| {
+        config.expect_ok(&["rustup", "toolchain", "install", "nightly"]);
+
+        let cwd = config.current_dir();
+        let test_rustupdir = cwd.join("rustup-test");
+        let test_toolchains = test_rustupdir.join("toolchains");
+        fs::create_dir_all(&test_toolchains).unwrap();
+        symlink_dir(&config.rustupdir.join("toolchains"), &test_toolchains).unwrap();
+
+        let home_override = &[("RUSTUP_HOME", test_rustupdir.to_str().unwrap())];
+
+        let out = config.run("rustup", ["toolchain", "list"], home_override);
+        assert!(out.ok);
+        assert!(out.stdout.contains("nightly"));
+
+        let out = config.run("rustc", ["+nightly", "--version"], home_override);
+        assert!(out.ok);
+        assert!(out.stdout.contains("hash-nightly-2"));
+
+        let out = config.run(
+            "rustup",
+            ["toolchain", "uninstall", "nightly"],
+            home_override,
+        );
+        assert!(out.ok);
+        config.expect_stdout_ok(
+            &["rustup", "toolchain", "list"],
+            "no installed toolchains\n",
+        );
+    });
+}
+
 // issue #1297
 #[test]
 fn update_unavailable_rustc() {