add subcmd to repair some persistent state

src/error.rs

@@ -48,6 +48,9 @@ pub(crate) enum Main {
 
     #[error(transparent)]
     CheckConfigCommand(#[from] CheckConfigCommand),
+
+    #[error(transparent)]
+    RepairCommand(#[from] RepairCommand),
 }
 
 /// Errors returned from the `serve` CLI subcommand.
@@ -85,6 +88,28 @@ pub(crate) enum CheckConfigCommand {
     Config(#[from] Config),
 }
 
+/// Errors returned from the `repair` CLI subcommand.
+// Missing docs are allowed here since that kind of information should be
+// encoded in the error messages themselves anyway.
+#[allow(missing_docs)]
+#[derive(Error, Debug)]
+pub(crate) enum RepairCommand {
+    #[error("failed to load configuration")]
+    Config(#[from] Config),
+
+    #[error("failed to load or create the database")]
+    Database(#[source] crate::utils::error::Error),
+
+    #[error("failed to initialize services")]
+    InitializeServices(#[source] crate::utils::error::Error),
+
+    #[error("`server_name` change check failed")]
+    ServerNameChanged(#[from] ServerNameChanged),
+
+    #[error("repair \"{0}\" failed, restoring from a backup is recommended")]
+    Repair(&'static str, #[source] Box<dyn std::error::Error>),
+}
+
 /// Error generated if `server_name` has changed or if checking this failed
 // Missing docs are allowed here since that kind of information should be
 // encoded in the error messages themselves anyway.