More intuitive message for check failures

Author: Taaku18

bot.py

@@ -781,6 +781,8 @@ async def on_command_error(self, context, exception):
                                  command=str(context.command))
         elif isinstance(exception, commands.CommandNotFound):
             logger.warning(error('CommandNotFound: ' + str(exception)))
+        elif isinstance(exception, commands.CheckFailure):
+            logger.warning(error('CheckFailure: ' + str(exception)))
         else:
             logger.error(error('Unexpected exception:'), exc_info=exception)
 
@@ -915,6 +917,7 @@ async def autoupdate_loop(self):
 
             await asyncio.sleep(3600)
 
+
 if __name__ == '__main__':
     if os.name != 'nt':
         import uvloop

core/checks.py

@@ -1,4 +1,8 @@
+import logging
 from discord.ext import commands
+from core.utils import error
+
+logger = logging.getLogger('Modmail')
 
 
 def has_permissions(**perms):
@@ -33,11 +37,17 @@ async def predicate(ctx):
 
         resolved = ctx.channel.permissions_for(ctx.author)
 
-        return resolved.administrator or all(
+        has_perm = resolved.administrator or all(
             getattr(resolved, name, None) == value
             for name, value in perms.items()
         )
 
+        if not has_perm:
+            restrictions = ', '.join(f'{name.replace("_", " ").title()} ({"yes" if value else "no"})'
+                                     for name, value in perms.items())
+            logger.error(error(f'Command `{ctx.command.qualified_name}` processes '
+                               f'the following restrictions(s): {restrictions}.'))
+        return has_perm
     return commands.check(predicate)