idr what I changed

1 files changed, 24 insertions, 1 deletions

diff --git a/src/launcher/version.rs b/src/launcher/version.rs
index 08c3bb5..f4cdd6c 100644
--- a/src/launcher/version.rs
+++ b/src/launcher/version.rs
@@ -190,12 +190,31 @@ impl<'a, T: Into<VersionResult<'a>>> From<Option<T>> for VersionResult<'a> {
     }
 }
 
+#[derive(Debug)]
 pub enum VersionResolveError {
-    InheritanceLoop,
+    InheritanceLoop(String),
     MissingVersion(String),
     Unknown(Box<dyn Error>)
 }
 
+impl Display for VersionResolveError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            VersionResolveError::InheritanceLoop(s) => {
+                write!(f, "inheritance loop (saw {s} twice)")
+            },
+            VersionResolveError::MissingVersion(s) => {
+                write!(f, "unknown version {s}")
+            },
+            VersionResolveError::Unknown(err) => {
+                write!(f, "unknown error: {err}")
+            }
+        }
+    }
+}
+
+impl Error for VersionResolveError {}
+
 impl VersionList {
     pub async fn online(home: &Path) -> Result<VersionList, Box<dyn Error>> {
         let remote = RemoteVersionList::new().await?;
@@ -262,6 +281,10 @@ impl VersionList {
         let mut inherit = inherit.clone();
 
         loop {
+            if seen.insert(inherit.clone()) {
+                return Err(VersionResolveError::InheritanceLoop(inherit));
+            }
+            
             let inherited_ver = match self.get_version_lazy(inherit.as_str()) {
                 VersionResult::Complete(v) => Cow::Borrowed(v),
                 VersionResult::Remote(v) =>