Thanks for starting this. It was next on my list.

Looks like fsharp project wont work on anything prior to 4.5. We can probably split that build off for any <4.5.

I've been seeing requests for framework 3.5 support, although off the top of my head I can't think of how cumbersome that might be.

This looks good, although the FSharp package is failing because FSharp isnt supported at the net40 level.

@moh-hassan Any ideas on how to prevent it from building when doing a net40 build? We can probably separate it out somehow. The build is getting complicated... lol

Hi @ericnewton76 ,
You can use conditional build
Modify the xml project `CommandLine.csproj' and replace

	  <ItemGroup>
		<PackageReference Include="FSharp.Core" Version="4.5.1" Condition="'$(BuildTarget)' == 'fsharp'" />
	  </ItemGroup>

With Condition:

	  <ItemGroup Condition="'$(TargetFramework)' != 'net40' and '$(BuildTarget)' == 'fsharp'">
		<PackageReference Include="FSharp.Core" Version="4.5.1" Condition="'$(BuildTarget)' == 'fsharp'" />
	  </ItemGroup>

I generated Fsharp package by the command:

             msbuild /t:pack /p:BuildTarget=fsharp

I get a package: `CommandLineParser.FSharp.2.5.0.nupkg' in my modified pR
the package include net40,net45,net461 and netstandard2

Let me know i this done in your side, and ready for ping. I'm online now.

Can you check the generated package.
CommandLineParser.FSharp.2.5.0.nupkg.zip

@ericnewton76
To check that all tests pass in both net461 and netcoreapp2.0, I modified the Test Project as multi-target project:

            <TargetFrameworks>net461;netcoreapp2.0</TargetFrameworks>

I run dotnet test and find 14 test fail in net461 due to the reasons we discussed in the issue-389

I fixed the failed test by using the solution I explained in the same issue

All tests pass Successfully in both net461 and netcoreapp2.0
The PR support: net40,net45,net461,netstandard2.0,netcoreapp2.0 and Fsharp fix is included.

The test pass in CI Appveyor

with the green success text:

NET461

Test run for C:\projects\commandline\tests\CommandLine.Tests\bin\Debug\net461\CommandLine.Tests.dll(.NETFramework,Version=v4.6.1)
....
Total tests: 335. Passed: 335. Failed: 0. Skipped: 0.
Test Run Successful.

NETCoreApp2.0

Test run for C:\projects\commandline\tests\CommandLine.Tests\bin\Debug\netcoreapp2.0\CommandLine.Tests.dll(.NETCoreApp,Version=v2.0
...
Total tests: 335. Passed: 335. Failed: 0. Skipped: 0.
Test Run Successful.

The confliction in the merge is:

	<<<<<<< master
		<TargetFrameworks>netstandard2.0;net40;net45;net461;netcoreapp2.0</TargetFrameworks>
	=======
		<TargetFrameworks>netstandard2.0; net461; netcoreapp2.0</TargetFrameworks>
	>>>>>>> master

which can be resolved manually
Let me know if i missed something to do.

What's the status of this issue? It would be really great if it could be merged soon

@moh-hassan @ericnewton76
Is there any progress on this? Where does it stand? May I offer my assistance if needed?
We really need the library to be compatible with .NET 4.5 for our product.

The PR is ready to be merged:
It pass the unit test in netcoreapp2.0 and net461 and[ CI Appveyor](https://ci.appveyor.com/project
/moh-hassan/commandline)
It support: netstandard2.0;net40;net45;net461;netcoreapp2.0

The current Conflicting files:
src/CommandLine/CommandLine.csproj

  	  <<<<<<< master	
   <TargetFrameworks>netstandard2.0;net40;net45;net461;netcoreapp2.0</TargetFrameworks>
  	=======
  		<TargetFrameworks>netstandard2.0; net461; netcoreapp2.0</TargetFrameworks>
  	>>>>>>> master

It Can be resolved to:

	<TargetFrameworks>netstandard2.0;net40;net45;net461;netcoreapp2.0</TargetFrameworks>

tests/CommandLine.Tests/Unit/Text/HelpTextTests.cs

  <<<<<<< master
  	public class HelpTextTests: BaseTest
  =======
  	public class HelpTextTests : IDisposable
  >>>>>>> master

can be resolved to:

public class HelpTextTests: BaseTest,IDisposable 

@ericnewton76
Is there any modification that I can do for merging the PR

@vgalka-sl
The PR is ready to be merged after resolving the confliction as I explained above.

@vgalka-sl
The PR is ready to be merged after resolving the confliction as I explained above.

@moh-hassan Thank you! Seems Eric is busy, so we just have to wait.
Btw, maybe you can rebase and resolve the conflict yourself to make it "cleaner"?

@ericnewton76
@vgalka-sl

I have to resolve an error (not related to the current PR) after rebasing , may be due to merging a previous commit:

A compilation error:
Error CS0102 The type 'ErrorType' already contains a definition for 'VersionRequestedError'

'VersionRequestedError' is duplicated in the same file: Error.cs in line63 and line68

Also, resolving the following compilation errors:

• CS0160 A previous catch clause already catches all exceptions of this or of a super type ('Exception') CommandLine (commandline\src\CommandLine\Core\ReflectionExtensions.cs 113)
• Error CS0103 The name 'InvalidAttributeConfigurationError' does not exist in the current context CommandLine (src\CommandLine\Core\ReflectionExtensions.cs 115)

Can you confirm these modifications?

Edit:
There is a compilation error of the last merge. Have a look to this discussion.

The new PR#428 submitted by @Wind010 is fine and fix the issue of compilation errors and I can rebase Upstream after it's (PR#428) merged.

Moving the PR to a separate branch in a new PR# 430