This is where the build failed: mkdir -p -- ../class/lib/basic/ MCS [basic] basic.exe async.cs(15,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? class.cs(16,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? complete.cs(18,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? decl.cs(24,14): error CS0234: The type or namespace name `Xml' does not exist in the namespace `System'. Are you missing `System.Xml' assembly reference? doc.cs(19,14): error CS0234: The type or namespace name `Xml' does not exist in the namespace `System'. Are you missing `System.Xml' assembly reference? doc.cs(20,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? dynamic.cs(13,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? dynamic.cs(17,14): error CS0234: The type or namespace name `Dynamic' does not exist in the namespace `System'. Are you missing an assembly reference? ecore.cs(18,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? eval.cs(22,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? expression.cs(15,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? generic.cs(18,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? import.cs(14,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? location.cs(17,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? method.cs(20,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? method.cs(27,14): error CS0234: The type or namespace name `Xml' does not exist in the namespace `System'. Are you missing `System.Xml' assembly reference? namespace.cs(14,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? pending.cs(17,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? module.cs(18,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? typespec.cs(15,14): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? ../tools/monop/outline.cs(34,14): error CS0234: The type or namespace name `CodeDom' does not exist in the namespace `System'. Are you missing an assembly reference? dynamic.cs(14,20): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? ecore.cs(17,20): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? expression.cs(16,20): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? nullable.cs(16,20): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? cs-parser.jay(80,3): error CS0246: The type or namespace name `Stack' could not be found. Are you missing an assembly reference? cs-parser.jay(123,3): error CS0246: The type or namespace name `Stack' could not be found. Are you missing an assembly reference? cs-parser.jay(145,3): error CS0246: The type or namespace name `Stack' could not be found. Are you missing an assembly reference? ecore.cs(1311,22): error CS0426: The nested type `Expression' does not exist in the type `<error>' assign.cs(367,26): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? argument.cs(596,24): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? expression.cs(7309,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(7314,21): error CS0426: The nested type `Expression' does not exist in the type `<error>' dynamic.cs(212,7): error CS0426: The nested type `Expression' does not exist in the type `<error>' ecore.cs(6681,14): error CS0426: The nested type `Expression' does not exist in the type `<error>' ecore.cs(6686,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' cs-tokenizer.cs(244,3): error CS0308: The non-generic type `System.Collections.Stack' cannot be used with the type arguments /usr/lib64/mono/4.5/mscorlib.dll (Location of the symbol related to previous error) cs-tokenizer.cs(302,19): error CS0246: The type or namespace name `HashSet' could not be found. Are you missing an assembly reference? cs-tokenizer.cs(376,3): error CS0308: The non-generic type `System.Collections.Stack' cannot be used with the type arguments /usr/lib64/mono/4.5/mscorlib.dll (Location of the symbol related to previous error) cs-tokenizer.cs(400,3): error CS0308: The non-generic type `System.Collections.Stack' cannot be used with the type arguments /usr/lib64/mono/4.5/mscorlib.dll (Location of the symbol related to previous error) cs-tokenizer.cs(410,11): error CS0308: The non-generic type `System.Collections.Stack' cannot be used with the type arguments /usr/lib64/mono/4.5/mscorlib.dll (Location of the symbol related to previous error) cs-tokenizer.cs(416,11): error CS0308: The non-generic type `System.Collections.Stack' cannot be used with the type arguments /usr/lib64/mono/4.5/mscorlib.dll (Location of the symbol related to previous error) constant.cs(447,26): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? delegate.cs(956,26): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? doc.cs(32,12): error CS0246: The type or namespace name `XmlDocument' could not be found. Are you missing an assembly reference? doc.cs(40,3): error CS0246: The type or namespace name `XmlWriter' could not be found. Are you missing an assembly reference? doc.cs(48,22): error CS0246: The type or namespace name `XmlDocument' could not be found. Are you missing an assembly reference? doc.cs(84,3): error CS0246: The type or namespace name `XmlNode' could not be found. Are you missing an assembly reference? doc.cs(170,38): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? doc.cs(228,34): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? doc.cs(236,38): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? doc.cs(244,40): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? doc.cs(252,47): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? doc.cs(273,50): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? doc.cs(319,41): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? doc.cs(562,83): error CS0246: The type or namespace name `XmlElement' could not be found. Are you missing an assembly reference? dynamic.cs(75,12): error CS0246: The type or namespace name `DynamicMetaObject' could not be found. Are you missing an assembly reference? dynamic.cs(77,34): error CS0246: The type or namespace name `DynamicMetaObject' could not be found. Are you missing an assembly reference? dynamic.cs(88,10): error CS0246: The type or namespace name `DynamicMetaObject' could not be found. Are you missing an assembly reference? dynamic.cs(138,14): error CS0426: The nested type `Expression' does not exist in the type `<error>' dynamic.cs(143,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' dynamic.cs(185,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' ecore.cs(1475,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' ecore.cs(2419,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' ecore.cs(7260,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' ecore.cs(6832,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' ecore.cs(6841,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(92,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(732,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(1426,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(4316,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(4321,14): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(5850,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(7691,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(8327,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(10129,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(10651,14): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(10660,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(10665,7): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(10843,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(10860,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' expression.cs(11276,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' literal.cs(80,26): error CS0234: The type or namespace name `Linq' does not exist in the namespace `System'. Are you missing `System.Core' assembly reference? nullable.cs(259,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' nullable.cs(1066,23): error CS0426: The nested type `Expression' does not exist in the type `<error>' report.cs(64,10): error CS0246: The type or namespace name `HashSet' could not be found. Are you missing an assembly reference? report.cs(558,13): error CS0246: The type or namespace name `HashSet' could not be found. Are you missing an assembly reference? report.cs(919,12): error CS0246: The type or namespace name `Stopwatch' could not be found. Are you missing an assembly reference? report.cs(920,3): error CS0246: The type or namespace name `Stopwatch' could not be found. Are you missing an assembly reference? settings.cs(176,3): error CS0246: The type or namespace name `HashSet' could not be found. Are you missing an assembly reference? ../class/Mono.CompilerServices.SymbolWriter/SourceMethodBuilder.cs(40,3): error CS0246: The type or namespace name `Stack' could not be found. Are you missing an assembly reference? ../tools/monop/outline.cs(63,2): error CS0246: The type or namespace name `IndentedTextWriter' could not be found. Are you missing an assembly reference? ../../external/ikvm/reflect/Emit/ILGenerator.cs(119,20): error CS0246: The type or namespace name `Stack' could not be found. Are you missing an assembly reference? Compilation failed: 93 error(s), 0 warnings
I resolved the issue as follows: Uninstalled all mono and dot-net/* packages. build mono with +minimal after that I could rebuild mono normally with libgdiplus
4.4.1.0 looks to build fine