rustracer: 2.1.48 -> 2.2.1

Update `rustracer` from 2.1.48 to 2.2.1 and unmark it as broken.

The breakage is now confined to its test suite, which therefore I disable.

pkgs/development/tools/rust/racer/default.nix

@@ -2,14 +2,14 @@
 
 rustPlatform.buildRustPackage rec {
   pname = "racer";
-  version = "2.1.48";
+  version = "2.2.1";
 
   src = fetchCrate {
     inherit pname version;
-    sha256 = "sha256-lat5s9+AMFI3VXiWqjLESZrtq3IwOZhlt+5BhYoonfA=";
+    sha256 = "sha256-uAVtJwOyhe1lPz+MUUFCgHJPVGuIk/lNUkQWiNdOZ5Y=";
   };
 
-  cargoSha256 = "sha256-jGsvCmrPGVzWdx7V3J4bBK+SF2o+icORmVKuwqYxdh4=";
+  cargoSha256 = "sha256-U2mI1y6t8CwxW/iPcPzxAafu61GNm/XLCKVGuyybV/4=";
 
   nativeBuildInputs = [ makeWrapper ];
   buildInputs = lib.optional stdenv.isDarwin Security;
@@ -32,6 +32,10 @@ rustPlatform.buildRustPackage rec {
     "--skip test_resolve_global_path_in_modules"
   ];
 
+  # [2022-04-06] Its test suite contains two function calls with the
+  # wrong number of arguments, breaking its build.
+  doCheck = false;
+
   doInstallCheck = true;
   installCheckPhase = ''
     $out/bin/racer --version
@@ -42,7 +46,5 @@ rustPlatform.buildRustPackage rec {
     homepage = "https://github.com/racer-rust/racer";
     license = licenses.mit;
     maintainers = with maintainers; [ jagajaga ];
-    # error[E0199]: implementing the trait `Step` is not unsafe
-    broken = true;
   };
 }