Source-generator diagnostics in .NET 6+
If your .NET 6+ project references a package that enables source generation of code, for example, a logging solution, then the analyzers that are specific to source generation will run at compile time. This article lists the compiler diagnostics related to source-generated code.
If you encounter one of these build warnings or errors, follow the specific guidance provided for the diagnostic ID listed in the Reference section. You can also suppress warnings using the specific SYSLIB1XXX diagnostic ID value. For more information, see Suppress warnings.
Analyzer warnings
The diagnostic ID values reserved for source-generated code analyzer warnings are SYSLIB1001 through SYSLIB1999.
Reference
The following table provides an index to the SYSLIB1XXX diagnostics in .NET 6 and later versions.
| Diagnostic ID | Description |
|---|---|
| SYSLIB1001 | Logging method names cannot start with _ |
| SYSLIB1002 | Don't include log level parameters as templates in the logging message |
| SYSLIB1003 | InvalidLoggingMethodParameterNameTitle |
| SYSLIB1004 | Logging class cannot be in nested types. |
| SYSLIB1005 | Could not find a required type definition |
| SYSLIB1006 | Multiple logging methods cannot use the same event ID within a class |
| SYSLIB1007 | Logging methods must return void |
| SYSLIB1008 | One of the arguments to a logging method must implement the Microsoft.Extensions.Logging.ILogger interface |
| SYSLIB1009 | Logging methods must be static |
| SYSLIB1010 | Logging methods must be partial |
| SYSLIB1011 | Logging methods cannot be generic |
| SYSLIB1012 | Redundant qualifier in logging message |
| SYSLIB1013 | Don't include exception parameters as templates in the logging message |
| SYSLIB1014 | Logging template has no corresponding method argument |
| SYSLIB1015 | Argument is not referenced from the logging message |
| SYSLIB1016 | Logging methods cannot have a body |
| SYSLIB1017 | A LogLevel value must be supplied in the LoggerMessage attribute or as a parameter to the logging method |
| SYSLIB1018 | Don't include logger parameters as templates in the logging message |
| SYSLIB1019 | Couldn't find a field of type Microsoft.Extensions.Logging.ILogger |
| SYSLIB1020 | Found multiple fields of type Microsoft.Extensions.Logging.ILogger |
| SYSLIB1021 | Multiple message-template item names differ only by case |
| SYSLIB1022 | Can't have malformed format strings (for example, dangling curly braces) |
| SYSLIB1023 | Generating more than six arguments is not supported |
| SYSLIB1024 | Logging method argument uses unsupported out parameter modifier |
| SYSLIB1025 | Multiple logging methods cannot use the same event name within a class |
| SYSLIB1026 | C# language version not supported by the logging source generator. |
| SYSLIB1027 | (Reserved for logging.) |
| SYSLIB1028 | (Reserved for logging.) |
| SYSLIB1029 | (Reserved for logging.) |
| SYSLIB1030 | The System.Text.Json source generator did not generate serialization metadata for type |
| SYSLIB1031 | The System.Text.Json source generator encountered a duplicate JsonTypeInfo property name |
| SYSLIB1032 | The System.Text.Json source generator encountered a context class that is not partial |
| SYSLIB1033 | The System.Text.Json source generator encountered a type that has multiple [JsonConstructor] annotations |
| SYSLIB1034 | JsonSourceGenerator encountered a JsonStringEnumConverter annotation |
| SYSLIB1035 | The System.Text.Json source generator encountered a type that has multiple [JsonExtensionData] annotations |
| SYSLIB1036 | The System.Text.Json source generator encountered an invalid [JsonExtensionData] annotation |
| SYSLIB1037 | The System.Text.Json source generator encountered a type with init-only properties for which deserialization is not supported |
| SYSLIB1038 | The System.Text.Json source generator encountered a property annotated with [JsonInclude] that has inaccessible accessors |
| SYSLIB1039 | JsonSourceGenerator encountered a JsonDerivedTypeAttribute annotation with JsonSourceGenerationMode.Serialization enabled |
| SYSLIB1040 | Invalid GeneratedRegexAttribute usage. |
| SYSLIB1041 | Multiple GeneratedRegexAttribute attributes were applied to the same method, but only one is allowed. |
| SYSLIB1042 | The specified regular expression is invalid. |
| SYSLIB1043 | A GeneratedRegexAttribute method must be partial, parameterless, non-generic, and non-abstract, and return Regex. |
| SYSLIB1044 | The regex generator couldn't generate a complete source implementation for the specified regular expression due to an internal limitation. See the explanation in the generated source for more details. |
| SYSLIB1045 | Use GeneratedRegexAttribute to generate the regular expression implementation at compile time. |
| SYSLIB1046 | (Reserved for System.Text.RegularExpressions.Generator.) |
| SYSLIB1047 | (Reserved for System.Text.RegularExpressions.Generator.) |
| SYSLIB1048 | (Reserved for System.Text.RegularExpressions.Generator.) |
| SYSLIB1049 | (Reserved for System.Text.RegularExpressions.Generator.) |
| SYSLIB1050 | Invalid LibraryImportAttribute usage. |
| SYSLIB1051 | The specified type is not supported by source-generated p/invokes. |
| SYSLIB1052 | The specified configuration is not supported by source-generated p/invokes. |
| SYSLIB1053 | The specified LibraryImportAttribute arguments cannot be forwarded to DllImportAttribute. |
| SYSLIB1054 | Use LibraryImportAttribute instead of DllImportAttribute to generate p/invoke marshalling code at compile time. |
| SYSLIB1055 | Invalid CustomMarshallerAttribute usage. |
| SYSLIB1056 | The specified native type is invalid. |
| SYSLIB1057 | The marshaller type does not have the required shape. |
| SYSLIB1058 | Invalid NativeMarshallingAttribute usage. |
| SYSLIB1059 | The marshaller type does not support an allocating constructor. |
| SYSLIB1060 | The specified marshaller type is invalid. |
| SYSLIB1061 | The marshaller type has incompatible method signatures. |
| SYSLIB1062 | The project must be updated with <AllowUnsafeBlocks>true</AllowUnsafeBlocks>. |
| SYSLIB1063 | (Reserved for Microsoft.Interop.LibraryImportGenerator.) |
| SYSLIB1064 | (Reserved for Microsoft.Interop.LibraryImportGenerator.) |
| SYSLIB1065 | (Reserved for Microsoft.Interop.LibraryImportGenerator.) |
| SYSLIB1066 | (Reserved for Microsoft.Interop.LibraryImportGenerator.) |
| SYSLIB1067 | (Reserved for Microsoft.Interop.LibraryImportGenerator.) |
| SYSLIB1068 | (Reserved for Microsoft.Interop.LibraryImportGenerator.) |
| SYSLIB1069 | (Reserved for Microsoft.Interop.LibraryImportGenerator.) |
| SYSLIB1070 | Invalid JSImportAttribute usage. |
| SYSLIB1071 | Invalid JSExportAttribute usage. |
| SYSLIB1072 | The specified type is not supported by source-generated JavaScript interop. |
| SYSLIB1073 | The specified configuration is not supported by source-generated JavaScript interop. |
| SYSLIB1074 | JSImportAttribute requires unsafe code. |
| SYSLIB1075 | JSImportAttribute requires unsafe code. |
| SYSLIB1076 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1077 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1078 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1079 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1080 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1081 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1082 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1083 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1084 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1085 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1086 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1087 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1088 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1089 | (Reserved for System.Runtime.InteropServices.JavaScript.JSImportGenerator.) |
| SYSLIB1090 | Invalid GeneratedComInterfaceAttribute usage. |
| SYSLIB1091 | Method is declared in different partial declaration than the GeneratedComInterface attribute. |
| SYSLIB1092 | Usage of LibraryImport or GeneratedComInterface attribute does not follow recommendation. |
| SYSLIB1093 | Analysis for COM interface generation has failed. |
| SYSLIB1094 | The base COM interface failed to generate source. Code will not be generated for this interface. |
| SYSLIB1095 | Invalid GeneratedComClassAttribute usage. |
| SYSLIB1096 | Use GeneratedComInterfaceAttribute instead of ComImportAttribute to generate COM marshalling code at compile time. |
| SYSLIB1097 | This type implements at least one type with the GeneratedComInterfaceAttribute attribute. Add the GeneratedComClassAttribute to enable passing this type to COM and exposing the COM interfaces for the types with the GeneratedComInterfaceAttribute from objects of this type. |
| SYSLIB1098 | .NET COM hosting with EnableComHosting only supports built-in COM interop. It does not support source-generated COM interop with GeneratedComInterfaceAttribute. |
| SYSLIB1099 | COM Interop APIs on System.Runtime.InteropServices.Marshal do not support source-generated COM and will fail at run time. |
| SYSLIB1100 | Configuration binding generator: Type is not supported. |
| SYSLIB1101 | Configuration binding generator: Property on type is not supported. |
| SYSLIB1102 | Configuration binding generator: Project's language version must be at least C# 12. |
| SYSLIB1103 | Configuration binding generator: Value types are invalid inputs to configuration 'Bind' methods. |
| SYSLIB1104 | Configuration binding generator: Generator cannot determine the target configuration type. |
| SYSLIB1105 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1106 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.)(Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1107 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1108 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1109 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1110 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1111 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1112 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1113 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1114 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1115 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1116 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1117 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1118 | (Reserved for Microsoft.Extensions.Configuration.Binder.SourceGeneration.) |
| SYSLIB1201 | Can't use ValidateObjectMembersAttribute or ValidateEnumeratedItemsAttribute on fields or properties with open generic types. |
| SYSLIB1202 | A member type has no fields or properties to validate. |
| SYSLIB1203 | A type has no fields or properties to validate. |
| SYSLIB1204 | A type annotated with OptionsValidatorAttribute doesn't implement the necessary interface. |
| SYSLIB1205 | A type already includes an implementation of the 'Validate' method. |
| SYSLIB1206 | Can't validate private fields or properties. |
| SYSLIB1207 | Member type is not enumerable. |
| SYSLIB1208 | Validators used for transitive or enumerable validation must have a constructor with no parameters. |
| SYSLIB1209 | OptionsValidatorAttribute can't be applied to a static class. |
| SYSLIB1210 | Null validator type specified for the ValidateObjectMembersAttribute or ValidateEnumeratedItemsAttribute attributes. |
| SYSLIB1211 | Unsupported circular references in model types. |
| SYSLIB1212 | Member potentially missing transitive validation. |
| SYSLIB1213 | Member potentially missing enumerable validation. |
| SYSLIB1214 | Can't validate constants, static fields, or properties. |
| SYSLIB1215 | Validation attribute on the member is inaccessible from the validator type. |
| SYSLIB1216 | C# language version not supported by the options validation source generator. |
| SYSLIB1217 | The validation attribute is only applicable to properties of type string, array, or ICollection; it cannot be used with other types. |
| SYSLIB1218 | (Reserved for Microsoft.Extensions.Options.SourceGeneration.) |
| SYSLIB1219 | (Reserved for Microsoft.Extensions.Options.SourceGeneration.) |
| SYSLIB1220 | JsonSourceGenerator encountered a [JsonConverterAttribute] with an invalid type argument. |
| SYSLIB1221 | JsonSourceGenerator does not support this C# language version. |
| SYSLIB1222 | Constructor annotated with JsonConstructorAttribute is inaccessible. |
| SYSLIB1223 | Constructor annotated with JsonConstructorAttribute is inaccessible. |
| SYSLIB1224 | Types annotated with JsonSerializableAttribute must be classes deriving from JsonSerializerContext. |
| SYSLIB1225 | (Reserved for System.Text.Json.SourceGeneration.) |
| SYSLIB1226 | (Reserved for System.Text.Json.SourceGeneration.) |
| SYSLIB1227 | (Reserved for System.Text.Json.SourceGeneration.) |
| SYSLIB1228 | (Reserved for System.Text.Json.SourceGeneration.) |
| SYSLIB1229 | (Reserved for System.Text.Json.SourceGeneration.) |
Suppress warnings
It's recommended that you use one of the workarounds when possible. However, if you cannot change your code, you can suppress the warning through a #pragma directive or a <NoWarn> project setting. If the SYSLIB1XXX source generator diagnostic doesn't surface as an error, you can suppress the warning in code or in your project file.
To suppress the warnings in code:
// Disable the warning.
#pragma warning disable SYSLIB1006
// Code that generates compiler diagnostic.
// ...
// Re-enable the warning.
#pragma warning restore SYSLIB1006
To suppress the warnings in a project file:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>net6.0</TargetFramework>
<!-- NoWarn below suppresses SYSLIB1002 project-wide -->
<NoWarn>$(NoWarn);SYSLIB1002</NoWarn>
<!-- To suppress multiple warnings, you can use multiple NoWarn elements -->
<NoWarn>$(NoWarn);SYSLIB1002</NoWarn>
<NoWarn>$(NoWarn);SYSLIB1006</NoWarn>
<!-- Alternatively, you can suppress multiple warnings by using a semicolon-delimited list -->
<NoWarn>$(NoWarn);SYSLIB1002;SYSLIB1006;SYSLIB1007</NoWarn>
</PropertyGroup>
</Project>
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