Update setup.md

docs/docs/setup.md

@@ -10,8 +10,9 @@ How to build, test, and run a-mir-formality:
     * run `nix-shell` if you have nix available to get everything set up automatically
     * For tips on running without X11 on linux / wsl, see FAQ below.
 * Check out the a-mir-formality repository
-* Run `raco test -j 22 src` to run the tests
-    * This will use 22 parallel threads; you may want to tune the number depending on how many cores you have.
+* Run `raco test -t -j 22 src` to run the tests
+    * The `-t` option prints a summary table at the end so you can see which modules had failures.
+    * The `-j 22` option uses 22 parallel threads; you may want to tune the number depending on how many cores you have (N.B. `-j22` does not work).
 * You can use [DrRacket](https://docs.racket-lang.org/drracket/), or you can use VSCode. We recommend the following VSCode extensions:
     * [Magic Racket](https://marketplace.visualstudio.com/items?itemName=evzen-wybitul.magic-racket) to give a Racket mode that supports most LSP operations decently well
         * Note that you have to run `raco pkg install racket-langserver`!