Compile LanguageExt on MacOS

[gregberns]

In an attempt to contribute, I've attempted to build the LanguageExt project locally, but cannot on MacOS. When I run dotnet build it emits some warnings then just starts dumping thousands of errors.

The error repeated is "Predefined type 'System.Object' ...." which seems to signal I'm missing something fundamental.

Since the project has Net46 as a target, I'd assume it requires Mono to build (which I'm not too familiar with), but I'd assume I'm missing something there. I tried to find a flag to use to only build with the NetStandard no luck.

Tried to build specifying the target framework, but I'm not sure whether this is correct: dotnet build -p:AppTargetFramework=netstandard2.1. Attempted to build specifying the mono framework dotnet build /p:TargetFrameworkRootPath=/Library/Frameworks/Mono.framework/Versions/Current/Commands/mono

Any thoughts on what I might be missing?

Sample of warnings emitted before errors, which seem to signal I'm missing something critical.

/usr/local/share/dotnet/sdk/3.1.401/Microsoft.Common.CurrentVersion.targets(2084,5): warning MSB3245: Could not resolve this reference. Could not locate the assembly "mscorlib". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]
/usr/local/share/dotnet/sdk/3.1.401/Microsoft.Common.CurrentVersion.targets(2084,5): warning MSB3245: Could not resolve this reference. Could not locate the assembly "System". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]
/usr/local/share/dotnet/sdk/3.1.401/Microsoft.Common.CurrentVersion.targets(2084,5): warning MSB3245: Could not resolve this reference. Could not locate the assembly "System.Data". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]

Sample of errors:

DataTypes/Either/Either.cs(1011,25): error CS0518: Predefined type 'System.ValueType' is not defined or imported [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]
DataTypes/Either/Either.cs(1011,25): error CS0518: Predefined type 'System.Object' is not defined or imported [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]
ClassInstances/Applicative/ApplValueTask.cs(33,33): error CS0518: Predefined type 'System.ValueType' is not defined or imported [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]
ClassInstances/Applicative/ApplValueTask.cs(33,33): error CS0518: Predefined type 'System.Object' is not defined or imported [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]
ClassInstances/Applicative/ApplValueTask.cs(33,33): error CS0012: The type 'ValueType' is defined in an assembly that is not referenced. You must add a reference to assembly 'mscorlib, Version=0.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. [/Users/gb/github/language-ext/LanguageExt.Core/LanguageExt.Core.csproj]

DotNet Info:

dotnet --info                                    
.NET Core SDK (reflecting any global.json):
 Version:   3.1.401
 Commit:    39d17847db

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.15
 OS Platform: Darwin
 RID:         osx.10.15-x64
 Base Path:   /usr/local/share/dotnet/sdk/3.1.401/

Host (useful for support):
  Version: 3.1.7
  Commit:  fcfdef8d6b

.NET Core SDKs installed:
  2.1.811 [/usr/local/share/dotnet/sdk]
  3.1.401 [/usr/local/share/dotnet/sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.23 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.23 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.7 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.23 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.7 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

Mono version

mono --version
Mono JIT compiler version 6.12.0.90 (2020-02/d3daacdaa80 Thu Jul 30 16:18:06 EDT 2020)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           
	SIGSEGV:       altstack
	Notification:  kqueue
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug 
	Interpreter:   yes
	LLVM:          yes(610)
	Suspend:       hybrid
	GC:            sgen (concurrent by default)

[gregberns]

This will do it (Source):

dotnet build -f netstandard2.1

I can get everything to compile manually running dotnet build and specifying the right framework version on each project individually.

CodeGen is still on netstandard2.0. Might be worth bringing that up to date.

Could we create a Contribution document to put this any anything else helpful into?

# Works
dotnet build LanguageExt.CodeGen -f netstandard2.1
dotnet build LanguageExt.FSharp -f netstandard2.1
dotnet build LanguageExt.Parsec -f netstandard2.1
dotnet build LanguageExt.Rx -f netstandard2.1

Fails with netstandard2.1:

$ dotnet build LanguageExt.Benchmarks -f netstandard2.1
/usr/local/share/dotnet/sdk/3.1.401/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(241,5): error NETSDK1005: Assets file '/Users/gb/github/language-ext/LanguageExt.Benchmarks/obj/project.assets.json' doesn't have a target for '.NETStandard,Version=v2.1'. Ensure that restore has run and that you have included 'netstandard2.1' in the TargetFrameworks for your project.
$ dotnet build LanguageExt.CodeGen -f netstandard2.1
/usr/local/share/dotnet/sdk/3.1.401/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(241,5): error NETSDK1005: Assets file '/Users/gb/github/language-ext/LanguageExt.CodeGen/obj/project.assets.json' doesn't have a target for '.NETStandard,Version=v2.1'. Ensure that restore has run and that you have included 'netstandard2.1' in the TargetFrameworks for your project.
$ dotnet build LanguageExt.Tests -f netstandard2.1
/usr/local/share/dotnet/sdk/3.1.401/Sdks/Microsoft.NET.Sdk/targets/Microsoft.PackageDependencyResolution.targets(241,5): error NETSDK1005: Assets file '/Users/gb/github/language-ext/LanguageExt.Tests/obj/project.assets.json' doesn't have a target for '.NETStandard,Version=v2.1'. Ensure that restore has run and that you have included 'netstandard2.1' in the TargetFrameworks for your project.

But I can get the projects working by specifying a supported version:

# Works
dotnet build LanguageExt.CodeGen -f netstandard2.0
dotnet build LanguageExt.Tests -f netcoreapp3.1
dotnet build LanguageExt.Benchmarks -f netcoreapp3.0

[louthy]

Thanks Greg, I'll move this to Discussions for others to follow