Report unrecognized shorthands when loading from the root module

crates/compiler/load/tests/platform.roc

@@ -2,6 +2,7 @@ platform "test-platform"
     requires {} { main : * }
     exposes []
     packages {}
+    imports []
     provides [mainForHost]
 
 mainForHost : {} -> {}

crates/compiler/load/tests/test_reporting.rs

@@ -11670,6 +11670,54 @@ In roc, functions are always written as a lambda, like{}
     @r"
     "
     );
+    test_report!(
+        unknown_shorthand_no_deps,
+        indoc!(
+            r#"
+            import foo.Foo
+
+            Foo.foo
+            "#
+        ),
+        @r###"
+    ── UNKNOWN PACKAGE in tmp/unknown_shorthand_no_deps/Test.roc ───────────────────
+
+    This module is trying to import from `foo`:
+
+    4│      import foo.Foo
+                   ^^^^^^^
+
+    A lowercase name indicates a package shorthand, but no packages have
+    been specified.
+    "###
+    );
+
+    test_report!(
+        unknown_shorthand_in_app,
+        indoc!(
+            r#"
+            app [main] { pf: platform "../../tests/platform.roc" }
+
+            import foo.Foo
+
+            main =
+                Foo.foo
+            "#
+        ),
+        @r###"
+    ── UNKNOWN PACKAGE in tmp/unknown_shorthand_in_app/Test.roc ────────────────────
+
+    This module is trying to import from `foo`:
+
+    3│  import foo.Foo
+               ^^^^^^^
+
+    A lowercase name indicates a package shorthand, but I don't recognize
+    this one. Did you mean one of these?
+
+        pf
+    "###
+    );
 
     test_report!(
         invalid_toplevel_cycle,