fix(bot): clean up "not found in cache" errors in sentry

Myriad/Extensions/CacheExtensions.cs

@@ -9,14 +9,14 @@ public static class CacheExtensions
     public static async Task<Guild> GetGuild(this IDiscordCache cache, ulong guildId)
     {
         if (!(await cache.TryGetGuild(guildId) is Guild guild))
-            throw new KeyNotFoundException($"Guild {guildId} not found in cache");
+            throw new NotFoundInCacheException(guildId, "guild");
         return guild;
     }
 
     public static async Task<Channel> GetChannel(this IDiscordCache cache, ulong guildId, ulong channelId)
     {
         if (!(await cache.TryGetChannel(guildId, channelId) is Channel channel))
-            throw new KeyNotFoundException($"Channel {channelId} not found in cache");
+            throw new NotFoundInCacheException(channelId, "channel");
         return channel;
     }
 
@@ -55,3 +55,15 @@ public static class CacheExtensions
         return parent;
     }
 }
+
+public class NotFoundInCacheException: Exception
+{
+    public ulong EntityId { get; init; }
+    public string EntityType { get; init; }
+
+    public NotFoundInCacheException(ulong id, string type) : base("expected entity in discord cache but was not found")
+    {
+        EntityId = id;
+        EntityType = type;
+    }
+}

PluralKit.Bot/Bot.cs

@@ -213,6 +213,13 @@ public class Bot
     {
         _metrics.Measure.Meter.Mark(BotMetrics.BotErrors, exc.GetType().FullName);
 
+        if (exc is Myriad.Extensions.NotFoundInCacheException ce)
+        {
+            var scope = serviceScope.Resolve<Scope>();
+            scope.SetTag("entity.id", ce.EntityId.ToString());
+            scope.SetTag("entity.type", ce.EntityType);
+        }
+
         // Make this beforehand so we can access the event ID for logging
         var sentryEvent = new SentryEvent(exc);
 

PluralKit.Tests/packages.lock.json

@@ -949,6 +949,7 @@
           "Microsoft.AspNetCore.Mvc.Versioning": "[5.1.0, )",
           "Microsoft.AspNetCore.Mvc.Versioning.ApiExplorer": "[5.1.0, )",
           "PluralKit.Core": "[1.0.0, )",
+          "Sentry": "[4.13.0, )",
           "Serilog.AspNetCore": "[9.0.0, )"
         }
       },