This introduces the bug as well (see 2 latest commits)

crates/sub_lib_gherkin/src/sub_lib/mod.rs

@@ -1,25 +1,11 @@
 use cucumber::*;
 use sub_lib::Cat;
 
+pub mod steps;
+
 // `World` is your shared, likely mutable state.
 // Cucumber constructs it via `Default::default()` for each scenario.
 #[derive(Debug, Default, World)]
 pub struct AnimalWorld {
     pub(crate) cat: Cat,
 }
-
-// Steps are defined with `given`, `when` and `then` attributes.
-#[given("a hungry cat")]
-pub fn hungry_cat(world: &mut AnimalWorld) {
-    world.cat.hungry = true;
-}
-
-#[when("I feed the cat")]
-pub fn feed_cat(world: &mut AnimalWorld) {
-    world.cat.feed();
-}
-
-#[then("the cat is not hungry")]
-pub fn cat_is_fed(world: &mut AnimalWorld) {
-    assert!(!world.cat.hungry);
-}

crates/sub_lib_gherkin/src/sub_lib/steps.rs

@@ -0,0 +1,19 @@
+use cucumber::*;
+
+use super::AnimalWorld;
+
+// Steps are defined with `given`, `when` and `then` attributes.
+#[given("a hungry cat")]
+pub fn hungry_cat(world: &mut AnimalWorld) {
+    world.cat.hungry = true;
+}
+
+#[when("I feed the cat")]
+pub fn feed_cat(world: &mut AnimalWorld) {
+    world.cat.feed();
+}
+
+#[then("the cat is not hungry")]
+pub fn cat_is_fed(world: &mut AnimalWorld) {
+    assert!(!world.cat.hungry);
+}