Code that compiled using SDK 8.0.250 fails to compile when using SDK 8.0.300 with error CS0121

[michelemottini]

Describe the bug

Compiling some code that works fine with SDK 8.0.250 and Visual Studio 17.9.7 fails with error CS0121 The call is ambiguous between the following methods when using SDK 8.0.300

To Reproduce

• Install .NET SDK 8.0.300
• Clone https://github.com/michelemottini/SdkBug
• Execute dotnet build .\SdkBug.csproj:

  Determining projects to restore...
  All projects are up-to-date for restore.
C:\temp\SdkBug\Program.cs(4,24): error CS0121: The call is ambiguous between the following methods or properties: 'Test
<TIntermediate>.X<TElement>(params Expression<Func<TIntermediate, TElement>>[])' and 'Test<TIntermediate>.X<TElement>(p
arams Expression<Func<TIntermediate, List<TElement>>>[])' [C:\temp\SdkBug\SdkBug.csproj]

Build FAILED.

C:\temp\SdkBug\Program.cs(4,24): error CS0121: The call is ambiguous between the following methods or properties: 'Test
<TIntermediate>.X<TElement>(params Expression<Func<TIntermediate, TElement>>[])' and 'Test<TIntermediate>.X<TElement>(p
arams Expression<Func<TIntermediate, List<TElement>>>[])' [C:\temp\SdkBug\SdkBug.csproj]
    0 Warning(s)
    1 Error(s)

Time Elapsed 00:00:01.68

Further technical details

dotnet --info output:

.NET SDK:
 Version:           8.0.300
 Commit:            326f6e68b2
 Workload version:  8.0.300-manifests.cf0b4297
 MSBuild version:   17.10.4+10fbfbf2e

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19045
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\8.0.300\

.NET workloads installed:
There are no installed workloads to display.

Host:
  Version:      8.0.5
  Architecture: x64
  Commit:       087e15321b

.NET SDKs installed:
  2.1.526 [C:\Program Files\dotnet\sdk]
  3.1.120 [C:\Program Files\dotnet\sdk]
  3.1.426 [C:\Program Files\dotnet\sdk]
  5.0.214 [C:\Program Files\dotnet\sdk]
  6.0.130 [C:\Program Files\dotnet\sdk]
  8.0.205 [C:\Program Files\dotnet\sdk]
  8.0.300 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.19 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.19 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.30 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.19 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
  Not set

global.json file:
  Not found

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[cston]

Looks like a duplicate of #73346.

cc @AlekseyTs, @jaredpar

[michelemottini]

Ah yes, it looks like the same thing, thanks