Handle custom errors from subtensor

bittensor_cli/src/bittensor/extrinsics/registration.py

@@ -615,7 +615,10 @@ async def get_neuron_for_pubkey_and_subnet():
                         if not await response.is_success:
                             success, err_msg = (
                                 False,
-                                format_error_message(await response.error_message),
+                                format_error_message(
+                                    await response.error_message,
+                                    substrate=subtensor.substrate,
+                                ),
                             )
 
                     if not success:
@@ -786,7 +789,8 @@ async def run_faucet_extrinsic(
             await response.process_events()
             if not await response.is_success:
                 err_console.print(
-                    f":cross_mark: [red]Failed[/red]: {format_error_message(await response.error_message)}"
+                    f":cross_mark: [red]Failed[/red]: "
+                    f"{format_error_message(await response.error_message, subtensor.substrate)}"
                 )
                 if attempts == max_allowed_attempts:
                     raise MaxAttemptsException

bittensor_cli/src/bittensor/subtensor_interface.py

@@ -883,7 +883,9 @@ async def sign_and_send_extrinsic(
             if await response.is_success:
                 return True, ""
             else:
-                return False, format_error_message(await response.error_message)
+                return False, format_error_message(
+                    await response.error_message, substrate=self.substrate
+                )
         except SubstrateRequestException as e:
             return False, e
 

bittensor_cli/src/bittensor/utils.py

@@ -20,6 +20,9 @@
 
 if TYPE_CHECKING:
     from bittensor_cli.src.bittensor.chain_data import SubnetHyperparameters
+    from bittensor_cli.src.bittensor.async_substrate_interface import (
+        AsyncSubstrateInterface,
+    )
 
 console = Console()
 err_console = Console(stderr=True)
@@ -442,24 +445,65 @@ def get_explorer_url_for_network(
     return explorer_urls
 
 
-def format_error_message(error_message: dict) -> str:
+def format_error_message(
+    error_message: dict, substrate: "AsyncSubstrateInterface"
+) -> str:
     """
-    Formats an error message from the Subtensor error information to using in extrinsics.
+    Formats an error message from the Subtensor error information for use in extrinsics.
 
-    :param error_message: A dictionary containing the error information from Subtensor.
+    Args:
+        error_message: A dictionary containing the error information from Subtensor.
+        substrate: The substrate interface to use.
 
-    :return: A formatted error message string.
+    Returns:
+        str: A formatted error message string.
     """
-    err_type = "UnknownType"
     err_name = "UnknownError"
+    err_type = "UnknownType"
     err_description = "Unknown Description"
 
     if isinstance(error_message, dict):
-        err_type = error_message.get("type", err_type)
-        err_name = error_message.get("name", err_name)
-        err_docs = error_message.get("docs", [])
-        err_description = err_docs[0] if len(err_docs) > 0 else err_description
-    return f"Subtensor returned `{err_name} ({err_type})` error. This means: `{err_description}`"
+        # subtensor error structure
+        if (
+            error_message.get("code")
+            and error_message.get("message")
+            and error_message.get("data")
+        ):
+            err_name = "SubstrateRequestException"
+            err_type = error_message.get("message", "")
+            err_data = error_message.get("data", "")
+
+            # subtensor custom error marker
+            if err_data.startswith("Custom error:") and substrate:
+                if substrate.metadata:
+                    try:
+                        pallet = substrate.metadata.get_metadata_pallet(
+                            "SubtensorModule"
+                        )
+                        error_index = int(err_data.split("Custom error:")[-1])
+
+                        error_dict = pallet.errors[error_index].value
+                        err_type = error_dict.get("message", err_type)
+                        err_docs = error_dict.get("docs", [])
+                        err_description = err_docs[0] if err_docs else err_description
+                    except AttributeError:
+                        err_console.print(
+                            "Substrate pallets data unavailable. This is usually caused by an uninitialized substrate."
+                        )
+            else:
+                err_description = err_data
+
+        elif (
+            error_message.get("type")
+            and error_message.get("name")
+            and error_message.get("docs")
+        ):
+            err_type = error_message.get("type", err_type)
+            err_name = error_message.get("name", err_name)
+            err_docs = error_message.get("docs", [err_description])
+            err_description = err_docs[0] if err_docs else err_description
+
+    return f"Subtensor returned `{err_name}({err_type})` error. This means: `{err_description}`."
 
 
 def convert_blocks_to_time(blocks: int, block_time: int = 12) -> tuple[int, int, int]:

bittensor_cli/src/commands/subnets.py

@@ -129,7 +129,7 @@ async def _find_event_attributes_in_extrinsic_receipt(
         await response.process_events()
         if not await response.is_success:
             err_console.print(
-                f":cross_mark: [red]Failed[/red]: {format_error_message(await response.error_message)}"
+                f":cross_mark: [red]Failed[/red]: {format_error_message(await response.error_message, substrate)}"
             )
             await asyncio.sleep(0.5)
             return False

bittensor_cli/src/commands/weights.py

@@ -266,7 +266,9 @@ async def _do_set_weights():
             if await response.is_success:
                 return True, "Successfully set weights."
             else:
-                return False, format_error_message(await response.error_message)
+                return False, format_error_message(
+                    await response.error_message, self.subtensor.substrate
+                )
 
         with console.status(
             f":satellite: Setting weights on [white]{self.subtensor.network}[/white] ..."
@@ -327,7 +329,9 @@ async def reveal_weights_extrinsic(
             else:
                 success, error_message = (
                     False,
-                    format_error_message(await response.error_message),
+                    format_error_message(
+                        await response.error_message, self.subtensor.substrate
+                    ),
                 )
 
         if success: