Add backtrace to CI

.github/workflows/rust.yml

@@ -37,7 +37,7 @@ jobs:
       - uses: actions/checkout@v6
       - uses: swatinem/rust-cache@v2
       - name: cargo test
-        run: cargo test --workspace
+        run: RUST_BACKTRACE=1 cargo test --workspace
   dev-check:
     runs-on: ubuntu-latest
     steps:

tests/integration_tests.rs

@@ -38,6 +38,7 @@ impl<'a> Cmd<'a> {
         self
     }
 
+    #[track_caller]
     fn assert(&self, success: bool) {
         let rustlings_bin = {
             let mut path = env::current_exe().unwrap();
@@ -87,11 +88,13 @@ impl<'a> Cmd<'a> {
     }
 
     #[inline]
+    #[track_caller]
     fn success(&self) {
         self.assert(true);
     }
 
     #[inline]
+    #[track_caller]
     fn fail(&self) {
         self.assert(false);
     }