feat(cache): add proper cache read error

Author: ashleygwilliams

src/errors.rs

@@ -44,6 +44,12 @@ pub enum OrandaError {
     #[diagnostic(help("Please make sure you give a valid path pointing to a css file."))]
     InvalidOrandaCSSOverride { path: String },
 
+    #[error("Failed to read cached context.")]
+    CachedContextReadError {
+        #[source]
+        details: Box<OrandaError>,
+    },
+
     #[error("Failed fetching releases from Github.")]
     GithubReleasesFetchError {
         #[source]

src/site/mod.rs

@@ -52,7 +52,7 @@ impl Site {
                             Message::new(MessageType::Warning, "Using cached context...").print();
                             cached
                         }
-                        Err(e) => Err(OrandaError::Other("Failed to read cached context".to_string()))?
+                        Err(e) => Err(OrandaError::CachedContextReadError{ details: Box::new(e) })?
                     }
                 } else {
                     Context::new(repo_url, config.artifacts.cargo_dist())?