Fix toolchain repo aliases and add a test. (#3181)

Co-authored-by: UebelAndre <[email protected]>

.bazelci/presubmit.yml

@@ -585,6 +585,7 @@ tasks:
     working_directory: test/aliased_toolchains
     build_targets:
       - "@rust_toolchains//:all"
+      - "//..."
   android_examples_ubuntu2004:
     name: Android Examples
     platform: ubuntu2004

rust/repositories.bzl

@@ -269,7 +269,7 @@ def rust_register_toolchains(
             sha256s = sha256s,
             urls = urls,
             versions = versions,
-            aliases = aliases,
+            aliases = dict(aliases),
         )
 
         for toolchain in _get_toolchain_repositories(

test/aliased_toolchains/BUILD.bazel

@@ -0,0 +1,6 @@
+load("@rules_rust//rust:defs.bzl", "rust_library")
+
+rust_library(
+    name = "hello",
+    srcs = ["hello.rs"],
+)

test/aliased_toolchains/hello.rs

@@ -0,0 +1 @@
+pub fn hello() {}

test/empty_suite/BUILD.bazel

@@ -2,7 +2,7 @@ load("@rules_shell//shell:sh_test.bzl", "sh_test")
 load("//rust:defs.bzl", "rust_library", "rust_test", "rust_test_suite")
 
 # This package has a rust_test_suite containing no tests.
-# (This could happen if the srcs were seleceted via a glob).
+# (This could happen if the srcs were selected via a glob).
 #
 # We test that the test suite exists and is empty, bypassing test_suite's
 # special-case behavior for empty suites.