Release-only build error when using ParamsSource with a LINQ method: Cannot implicitly convert type 'object'

[cthompson92]

I believe this might be a bug in BDN 0.13.1, though I have tried 0.12.0 and 0.12.1 and had issues with those versions as well - granted, slightly different issues.

This is on Net6.0, in a solution with both C# and F# code.

0.13.1:

// Found 27 benchmarks:
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Blog1]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Blog2]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Blog3]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Blog4]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Blog5]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Blog6]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Blog7]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Quicksort1]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array1, FSharpBenchmark=Quicksort2]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Blog1]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Blog2]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Blog3]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Blog4]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Blog5]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Blog6]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Blog7]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Quicksort1]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array2, FSharpBenchmark=Quicksort2]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Blog1]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Blog2]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Blog3]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Blog4]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Blog5]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Blog6]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Blog7]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Quicksort1]
// InjectedFSharpQuicksortBenchmarks.FSharpQuicksorts: DefaultJob [FSharpData=FSharp - Array3, FSharpBenchmark=Quicksort2]
// Build Error: Standard output:
Standard error:
Time Elapsed 00:00:01.49
27 Error(s)
0 Warning(s)
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(12600,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(14796,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(14064,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(13332,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(11868,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(15528,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(11136,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(10404,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(16260,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(9672,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(8940,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(8208,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(7476,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(5280,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(6012,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(6744,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(16992,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(4548,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(17724,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(3816,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(3084,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(18456,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(2352,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(156,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(19188,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(1620,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(888,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
Build FAILED.
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(12600,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(14796,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(14064,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(13332,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(11868,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(15528,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(11136,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(10404,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(16260,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(9672,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(8940,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(8208,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(7476,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(5280,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(6012,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(6744,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(16992,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(4548,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(17724,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(3816,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(3084,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(18456,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(2352,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(156,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(19188,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(1620,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\08f4e2d5-bf72-436a-a197-73cf761f1905.notcs(888,35): error CS0266: Cannot implicitly convert type 'object' to 'Benchmarks.Abstract.IFSharpQuicksortDataSource'. An explicit conversion exists (are you missing a cast?) [D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905\BenchmarkDotNet.Autogenerated.csproj]
Copyright (C) Microsoft Corporation. All rights reserved.
Microsoft (R) Build Engine version 17.1.1+a02f73656 for .NET
// BenchmarkDotNet has failed to build the auto-generated boilerplate code.
// It can be found in D:\git\fsharp.project1\Benchmarks\bin\Release\net6.0\08f4e2d5-bf72-436a-a197-73cf761f1905
// Please follow the troubleshooting guide: https://benchmarkdotnet.org/articles/guides/troubleshooting.html
// ** Remained 0 benchmark(s) to run **
Run time: 00:00:00 (0.1 sec), executed benchmarks: 0

I've been able to narrow down the issue to this approach to generating parameterized benchmark data:

public class InjectedFSharpQuicksortBenchmarks
{
    private readonly Consumer consumer = new Consumer();

    public static IEnumerable<IFSharpQuicksortDataSource> FSharpDataSources()
    {
        // throws build error in RELEASE, but works in DEBUG compilation
        var converter = new CSharpToFSharpQuicksortDataSourceConverter();

        return InjectedCSharpQuicksortBenchmarks.CSharpDataSources().Select(x => converter.Convert(x));
    }

    [ParamsSource(nameof(FSharpDataSources))]
    public IFSharpQuicksortDataSource FSharpData { get; set; }

    public static IEnumerable<IFSharpQuicksortBenchmark> FSharpBenchmarks()
    {
        // omitted for brevity
    }

    [ParamsSource(nameof(FSharpBenchmarks))]
    public IFSharpQuicksortBenchmark FSharpBenchmark { get; set; }

    [Benchmark]
    public void FSharpQuicksorts()
    {
        FSharpBenchmark.Run(FSharpData.Data).Consume(consumer);
    }
}

However, if I change this approach to use classes directly, I do not encounter the issue:

public class InjectedFSharpQuicksortBenchmarks
{
    private readonly Consumer consumer = new Consumer();

    public static IEnumerable<IFSharpQuicksortDataSource> FSharpDataSources()
    {
        // works fine
        yield return new FSharpQuickSortArray1DataSource();
        yield return new FSharpQuickSortArray2DataSource();
        yield return new FSharpQuickSortArray3DataSource();
    }

    [ParamsSource(nameof(FSharpDataSources))]
    public IFSharpQuicksortDataSource FSharpData { get; set; }

    public static IEnumerable<IFSharpQuicksortBenchmark> FSharpBenchmarks()
    {
        // omitted for brevity
    }

    [ParamsSource(nameof(FSharpBenchmarks))]
    public IFSharpQuicksortBenchmark FSharpBenchmark { get; set; }

    [Benchmark]
    public void FSharpQuicksorts()
    {
        FSharpBenchmark.Run(FSharpData.Data).Consume(consumer);
    }
}

Related classes:

// multiple similar classes to this, with different int[] arrays 
public class CSharpQuicksortArray1DataSource : ICSharpQuicksortDataSource
{
    public string Category => "Array1";

    public int[] Data { get; } = BenchmarksData.A1;

    public override string ToString() => Category;
}

// packages up a CSharp int[] into an FSharpList<int> for the F# implementation
public class CSharpToFSharpQuicksortDataSourceConverter : ICSharpToFSharpQuicksortDataSourceConverter
{
    public IFSharpQuicksortDataSource Convert(ICSharpQuicksortDataSource data)
    {
        return new FSharpQuickSortDataSource(data.Data, data.Category);
    }

    private class FSharpQuickSortDataSource : IFSharpQuicksortDataSource
    {
        public FSharpList<int> Data { get; }
        public string Category { get; }
        
        public FSharpQuickSortDataSource(IEnumerable<int> data, string category)
        {
            Data = ListModule.OfSeq(data);
            Category = category;
        }
        
        public override string ToString()
        {
            return $"FSharp - {Category}";
        }
    }
}

// multiple similar classes to this, with different int[] arrays packaged into FSharpList<int>
public class FSharpQuickSortArray1DataSource : IFSharpQuicksortDataSource
{
    public string Category => "Array1";

    public FSharpList<int> Data { get; } = ListModule.OfSeq(BenchmarksData.A1);

    /// <summary>Returns a string that represents the current object.</summary>
    /// <returns>A string that represents the current object.</returns>
    public override string ToString() => Category;
}

I'm curious if I'm doing something that is strictly unsupported here, or if this is just an odd edge case I've found myself in.

Solution to reproduce this can be found here

[adamsitnik]

It looks like a BenchmarkDotNet bug. I won't have the time to fix it soon, but I am going to mark it as up-for-grabs, hoping that somebody else will.

[mawosoft]

This hasn't anything to do with Debug vs. Release or Linq.
The problem is that the data are provided by a private class implementing a public interface.
Minimal repro:

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Configs;
using BenchmarkDotNet.Jobs;
using BenchmarkDotNet.Running;
using BenchmarkDotNet.Toolchains.InProcess.Emit;

namespace ConsoleApp1
{
    public class Benchmarks1
    {
        public interface Interface1 {
            int Data { get; }
        }

        // Private class implements public interface.
        private class Private1 : Interface1
        {
            public int Data => 1;
        }

        public static IEnumerable<Interface1> DataSource()
        {
            // Returns the private class via public interface.
            yield return new Private1();
        }

        // BDN codegen ignores interface, recognizes non-public type Private1, tries to solve via base type,
        // which is System.Object:
        //   Benchmarks1_Instance.DataProperty = (Object) Benchmarks1.DataSource().ToArray()[0];
        [ParamsSource(nameof(DataSource))]
        public Interface1? DataProperty { get; set; }

        [Benchmark]
        public int Method1() => DataProperty?.Data ?? 0;
    }

    internal class Program
    {
        static void Main(string[] args)
        {
            // InProcess toolchain works regardless of Debug/Release
            ManualConfig config = ManualConfig.Create(DefaultConfig.Instance)
                .AddJob(Job.Dry.WithToolchain(InProcessEmitToolchain.DontLogOutput));
            _ = BenchmarkRunner.Run(typeof(Benchmarks1), config, args);

            // Regular toolchains don't work regardless of Debug/Release
            config = ManualConfig.Create(DefaultConfig.Instance)
                .AddJob(Job.Dry);
            _ = BenchmarkRunner.Run(typeof(Benchmarks1), config, args);
        }
    }
}

Whether that's a BDN bug or not is debatable.

[adamsitnik]

The problem is that the data are provided by a private class implementing a public interface.

@mawosoft thank you for investigating the issue!

Whether that's a BDN bug or not is debatable.

It's by design then. But, we could provide a nice error message instead of compilation failure.