pardeike/Harmony · error · ArgumentException

[ ]

Error message

{note} [{info.methodName}]

What it means

When Harmony performs a bulk patch (HarmonyPatchAll / TargetMethods style), target selection is done collectively, so individual patch methods must not also specify a target by name. A patch method carrying methodName alongside TargetMethod/TargetMethods/[HarmonyPatchAll] is ambiguous and is rejected.

Solutions

1. Remove the methodName from the patch method's HarmonyPatch/HarmonyMethod attribute and let TargetMethod/TargetMethods decide the target
2. Or remove TargetMethod/TargetMethods/[HarmonyPatchAll] from the class if you want per-method targeting
3. Keep target selection in exactly one place per patch class

Example fix

// before
[HarmonyPatch("Update")]
static void Postfix() { }
// class also has: static MethodBase TargetMethod() => ...
// after
static void Postfix() { } // target comes from TargetMethod()/TargetMethods()

var hasBulk = type.GetMethod("TargetMethod") != null || type.GetMethod("TargetMethods") != null || hasHarmonyPatchAll;
var bad = patchMethods.Where(p => p.info.methodName != null);

When it happens

Trigger: BulkPatch processing a patch method whose HarmonyMethod/HarmonyPatch info has a non-null methodName while the class also uses TargetMethod, TargetMethods, or [HarmonyPatchAll].

Common situations: Adding [HarmonyPatch("SomeMethod")] to a patch class that already defines a static TargetMethod(); copy-pasting annotated patch methods into an [HarmonyPatchAll] class; refactoring a class from individual annotations to bulk patching without cleaning attributes.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

• [ ]
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• cannot contain zeros
• Cannot directly reference dynamic method \
• Using requires an additional attribute for specifying the…

AI-assisted analysis of pardeike/Harmony@e7872dc170 (2026-09-15). Data as JSON: /api/errors/e5bbbda3315d77a0. Report an issue: GitHub.

Appendix: source

Thrown at Harmony/Public/PatchClassProcessor.cs:148

					lock (PatchProcessor.locker)
						_ = reversePatcher.Patch();
				}
			}
		}

		List<MethodInfo> BulkPatch(List<MethodBase> originals, ref MethodBase lastOriginal, bool unpatch)
		{
			var jobs = new PatchJobs<MethodInfo>();
			for (var i = 0; i < originals.Count; i++)
			{
				lastOriginal = originals[i];
				var job = jobs.GetJob(lastOriginal);
				foreach (var patchMethod in patchMethods)
				{
					var note = "You cannot combine TargetMethod, TargetMethods or [HarmonyPatchAll] with individual annotations";
					var info = patchMethod.info;
					if (info.methodName is not null)
						throw new ArgumentException($"{note} [{info.methodName}]");
					if (info.methodType.HasValue && info.methodType.Value != MethodType.Normal)
						throw new ArgumentException($"{note} [{info.methodType}]");
					if (info.argumentTypes is not null)
						throw new ArgumentException($"{note} [{info.argumentTypes.Description()}]");

					job.AddPatch(patchMethod);
				}
			}
			foreach (var job in jobs.GetJobs())
			{
				lastOriginal = job.original;
				if (unpatch)
					ProcessUnpatchJob(job);
				else
					ProcessPatchJob(job);
			}
			return jobs.GetReplacements();
		}

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