read repo_name when opening repos

fuzz/atom/parser/gencorpus.rs

@@ -20,7 +20,7 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     fs::create_dir_all(&corpus_dir)?;
 
-    let repo = Repo::new("/var/db/repos/gentoo");
+    let repo = Repo::new("/var/db/repos/gentoo").expect("failed to open repo");
     let mut atoms = Vec::new();
 
     for category in repo.categories()? {