Does not build with current Mono

[dundee]

I get this error, when building ironpython with current Mono (on Arch Linux):

$ make all
xbuild Build.proj /t:Build "/p:Mono=true;BaseConfiguration=Debug" /verbosity:minimal /nologo
				Configuration: Debug Platform: AnyCPU
			Configuration: Debug Platform: AnyCPU
		Configuration: Debug Platform: AnyCPU
	Configuration: Debug Platform: AnyCPU
ALINK:  warning A99999: Path 'policy.IronPython.config' in the resource name is not supported. Using just file name 'policy.IronPython.config'
Configuration: Debug Platform: AnyCPU
Configuration: Debug Platform: AnyCPU
socket.cs(1972,63): error CS0117: 'SocketOptionName' does not contain a definition for 'IPv6Only'
Configuration: Debug Platform: AnyCPU
Configuration: Debug Platform: AnyCPU
CSC: error CS8105: Attribute 'System.Reflection.AssemblyKeyNameAttribute' is ignored when public signing is specified.
Configuration: Debug Platform: AnyCPU
Configuration: Debug Platform: AnyCPU
CSC: error CS8105: Attribute 'System.Reflection.AssemblyKeyNameAttribute' is ignored when public signing is specified.
Configuration: Debug Platform: AnyCPU
CSC: error CS8105: Attribute 'System.Reflection.AssemblyKeyNameAttribute' is ignored when public signing is specified.
Configuration: Debug Platform: AnyCPU
CSC: error CS8105: Attribute 'System.Reflection.AssemblyKeyNameAttribute' is ignored when public signing is specified.
Configuration: Debug Platform: AnyCPU
Configuration: Debug Platform: AnyCPU
make: *** [Makefile:6: ironpython] Error 1

$ mono -V
Mono JIT compiler version 5.0.0 (Stable 5.0.0.100/9667aa6 Wed Jul 12 17:00:30 UTC 2017)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           __thread
	SIGSEGV:       altstack
	Notifications: epoll
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug 
	LLVM:          supported, not enabled.
	GC:            sgen (concurrent by default)

[slozier]

This repo is no longer maintained. Try building from https://github.com/IronLanguages/ironpython2 instead.