allow tiny ti delta

pallets/subtensor/src/utils/try_state.rs

@@ -38,10 +38,19 @@ impl<T: Config> Pallet<T> {
             .saturating_add(total_staked)
             .saturating_add(total_subnet_locked);
 
-        // Verify that the calculated total issuance matches the stored TotalIssuance
+        // Verify the diff between calculated TI and actual TI is less than delta
+        //
+        // These values can be off slightly due to float rounding errors.
+        // They are corrected every runtime upgrade.
+        const DELTA: u64 = 1000;
+        let diff = if TotalIssuance::<T>::get() > expected_total_issuance {
+            TotalIssuance::<T>::get() - expected_total_issuance
+        } else {
+            expected_total_issuance - TotalIssuance::<T>::get()
+        };
         ensure!(
-            TotalIssuance::<T>::get() == expected_total_issuance,
-            "TotalIssuance accounting discrepancy",
+            diff <= DELTA,
+            "TotalIssuance diff greater than allowable delta",
         );
 
         Ok(())

runtime/src/lib.rs

@@ -1082,6 +1082,8 @@ pub type SignedExtra = (
 );
 
 type Migrations =
+    // Leave this migration in the runtime to clean up tiny rounding errors (fractions of fractions
+    // of a cent) that occur due to floating point rounding errs every runtime upgrade.
     pallet_subtensor::migrations::migrate_init_total_issuance::initialise_total_issuance::Migration<
         Runtime,
     >;