Unable to execute when namespace-less assembly with CakeMethodAlias is referenced

[Sebazzz]

What You Are Seeing?

Error: System.ArgumentNullException: Value cannot be null.
Parameter name: imports[0]
   at Microsoft.CodeAnalysis.Scripting.ParameterValidationHelpers.AddRangeChecked[T](ArrayBuilder`1 builder, IEnumerable`1 items, String parameterName)
   at Microsoft.CodeAnalysis.Scripting.ParameterValidationHelpers.ConcatChecked[T](ImmutableArray`1 existing, IEnumerable`1 items, String parameterName)
   at Microsoft.CodeAnalysis.Scripting.ScriptOptions.AddImports(IEnumerable`1 imports)
   at Cake.Scripting.Roslyn.RoslynScriptSession.Execute(Script script)
   at Cake.Core.Scripting.ScriptRunner.Run(IScriptHost host, FilePath scriptPath, IDictionary`2 arguments)
   at Cake.Commands.BuildCommand.Execute(CakeOptions options)
   at Cake.CakeApplication.Run(CakeOptions options)
   at Cake.Program.Main()

What is Expected?

No crash - or at least a message that extensions without a namespace are not supported.

What version of Cake are you using?

0.22.0

Are you running on a 32 or 64 bit system?

64-bit

What environment are you running on? Windows? Linux? Mac?

Windows 7

Are you running on a CI Server? If so, which one?

N/A

How Did You Get This To Happen? (Steps to Reproduce)

1. Create an assembly with a class with a [CakeMethodAlias] attribute and don't put the class in the namespace.
2. #reference the assembly from a Cake script
3. #load the Cake script from step 2 in a parent Cake script

File from step 2:

#reference "BuildTools.7zip.dll"

File from step 3:

#load "BuildTools.7zip\tools\default.cake"

Output Log

C:\Users\[redacted]\Desktop\BuildTools.7zip>tools\packages\Cake\Cake.exe build.cake --verbosity=diagnostic
Module directory does not exist.
Analyzing build script...
Analyzing C:/Users/[redacted]/Desktop/BuildTools.7zip/build.cake...
Analyzing C:/Users/[redacted]/Desktop/BuildTools.7zip/BuildTools.7zip/tools/default.cake...
Analyzing C:/Users/[redacted]/Desktop/BuildTools.7zip/BuildTools.7zip/tools/load.cake...
Processing build script...
Verifying assembly 'BuildTools.7zip, Version=2.0.22.0, Culture=neutral, PublicKeyToken=null'.
Adding assembly reference to mscorlib.dll...
Adding assembly reference to System.Core.dll...
Adding assembly reference to Cake.Core.dll...
Adding assembly reference to Cake.Common.dll...
Adding assembly reference to Cake.exe...
Adding assembly reference to System.dll...
Adding assembly reference to System.Xml.dll...
Adding assembly reference to System.Xml.Linq.dll...
Adding assembly reference to System.Data.dll...
Adding assembly reference to System.Runtime.dll...
Adding assembly reference to BuildTools.7zip.dll...
Importing namespace [NULL]...
Importing namespace Cake.Common...
Importing namespace Cake.Common.Build...
Importing namespace Cake.Common.Build.AppVeyor...
Importing namespace Cake.Common.Build.AppVeyor.Data...
Importing namespace Cake.Common.Build.Bamboo...
Importing namespace Cake.Common.Build.Bamboo.Data...
Importing namespace Cake.Common.Build.BitbucketPipelines...
Importing namespace Cake.Common.Build.BitbucketPipelines.Data...
Importing namespace Cake.Common.Build.Bitrise...
Importing namespace Cake.Common.Build.Bitrise.Data...
Importing namespace Cake.Common.Build.ContinuaCI...
Importing namespace Cake.Common.Build.ContinuaCI.Data...
Importing namespace Cake.Common.Build.GitLabCI...
Importing namespace Cake.Common.Build.GitLabCI.Data...
Importing namespace Cake.Common.Build.GoCD...
Importing namespace Cake.Common.Build.GoCD.Data...
Importing namespace Cake.Common.Build.Jenkins...
Importing namespace Cake.Common.Build.Jenkins.Data...
Importing namespace Cake.Common.Build.MyGet...
Importing namespace Cake.Common.Build.TeamCity...
Importing namespace Cake.Common.Build.TFBuild...
Importing namespace Cake.Common.Build.TFBuild.Data...
Importing namespace Cake.Common.Build.TravisCI...
Importing namespace Cake.Common.Build.TravisCI.Data...
Importing namespace Cake.Common.Diagnostics...
Importing namespace Cake.Common.IO...
Importing namespace Cake.Common.IO.Paths...
Importing namespace Cake.Common.Net...
Importing namespace Cake.Common.Security...
Importing namespace Cake.Common.Solution...
Importing namespace Cake.Common.Solution.Project...
Importing namespace Cake.Common.Solution.Project.Properties...
Importing namespace Cake.Common.Solution.Project.XmlDoc...
Importing namespace Cake.Common.Text...
Importing namespace Cake.Common.Tools...
Importing namespace Cake.Common.Tools.Cake...
Importing namespace Cake.Common.Tools.Chocolatey...
Importing namespace Cake.Common.Tools.Chocolatey.ApiKey...
Importing namespace Cake.Common.Tools.Chocolatey.Config...
Importing namespace Cake.Common.Tools.Chocolatey.Download...
Importing namespace Cake.Common.Tools.Chocolatey.Features...
Importing namespace Cake.Common.Tools.Chocolatey.Install...
Importing namespace Cake.Common.Tools.Chocolatey.New...
Importing namespace Cake.Common.Tools.Chocolatey.Pack...
Importing namespace Cake.Common.Tools.Chocolatey.Pin...
Importing namespace Cake.Common.Tools.Chocolatey.Push...
Importing namespace Cake.Common.Tools.Chocolatey.Sources...
Importing namespace Cake.Common.Tools.Chocolatey.Uninstall...
Importing namespace Cake.Common.Tools.Chocolatey.Upgrade...
Importing namespace Cake.Common.Tools.DotCover...
Importing namespace Cake.Common.Tools.DotCover.Analyse...
Importing namespace Cake.Common.Tools.DotCover.Cover...
Importing namespace Cake.Common.Tools.DotCover.Merge...
Importing namespace Cake.Common.Tools.DotCover.Report...
Importing namespace Cake.Common.Tools.DotNetCore...
Importing namespace Cake.Common.Tools.DotNetCore.Build...
Importing namespace Cake.Common.Tools.DotNetCore.Clean...
Importing namespace Cake.Common.Tools.DotNetCore.Execute...
Importing namespace Cake.Common.Tools.DotNetCore.MSBuild...
Importing namespace Cake.Common.Tools.DotNetCore.NuGet.Delete...
Importing namespace Cake.Common.Tools.DotNetCore.NuGet.Push...
Importing namespace Cake.Common.Tools.DotNetCore.Pack...
Importing namespace Cake.Common.Tools.DotNetCore.Publish...
Importing namespace Cake.Common.Tools.DotNetCore.Restore...
Importing namespace Cake.Common.Tools.DotNetCore.Run...
Importing namespace Cake.Common.Tools.DotNetCore.Test...
Importing namespace Cake.Common.Tools.DotNetCore.Tool...
Importing namespace Cake.Common.Tools.DotNetCore.VSTest...
Importing namespace Cake.Common.Tools.DupFinder...
Importing namespace Cake.Common.Tools.Fixie...
Importing namespace Cake.Common.Tools.GitLink...
Importing namespace Cake.Common.Tools.GitReleaseManager...
Importing namespace Cake.Common.Tools.GitReleaseManager.AddAssets...
Importing namespace Cake.Common.Tools.GitReleaseManager.Close...
Importing namespace Cake.Common.Tools.GitReleaseManager.Create...
Importing namespace Cake.Common.Tools.GitReleaseManager.Export...
Importing namespace Cake.Common.Tools.GitReleaseManager.Publish...
Importing namespace Cake.Common.Tools.GitReleaseNotes...
Importing namespace Cake.Common.Tools.GitVersion...
Importing namespace Cake.Common.Tools.ILMerge...
Importing namespace Cake.Common.Tools.ILRepack...
Importing namespace Cake.Common.Tools.InnoSetup...
Importing namespace Cake.Common.Tools.InspectCode...
Importing namespace Cake.Common.Tools.MSBuild...
Importing namespace Cake.Common.Tools.MSTest...
Importing namespace Cake.Common.Tools.NSIS...
Importing namespace Cake.Common.Tools.NuGet...
Importing namespace Cake.Common.Tools.NuGet.Add...
Importing namespace Cake.Common.Tools.NuGet.Init...
Importing namespace Cake.Common.Tools.NuGet.Install...
Importing namespace Cake.Common.Tools.NuGet.Pack...
Importing namespace Cake.Common.Tools.NuGet.Push...
Importing namespace Cake.Common.Tools.NuGet.Restore...
Importing namespace Cake.Common.Tools.NuGet.SetApiKey...
Importing namespace Cake.Common.Tools.NuGet.SetProxy...
Importing namespace Cake.Common.Tools.NuGet.Sources...
Importing namespace Cake.Common.Tools.NuGet.Update...
Importing namespace Cake.Common.Tools.NUnit...
Importing namespace Cake.Common.Tools.OctopusDeploy...
Importing namespace Cake.Common.Tools.OpenCover...
Importing namespace Cake.Common.Tools.ReportGenerator...
Importing namespace Cake.Common.Tools.ReportUnit...
Importing namespace Cake.Common.Tools.Roundhouse...
Importing namespace Cake.Common.Tools.SignTool...
Importing namespace Cake.Common.Tools.SpecFlow...
Importing namespace Cake.Common.Tools.SpecFlow.StepDefinitionReport...
Importing namespace Cake.Common.Tools.SpecFlow.TestExecutionReport...
Importing namespace Cake.Common.Tools.TextTransform...
Importing namespace Cake.Common.Tools.VSTest...
Importing namespace Cake.Common.Tools.VSWhere...
Importing namespace Cake.Common.Tools.VSWhere.All...
Importing namespace Cake.Common.Tools.VSWhere.Latest...
Importing namespace Cake.Common.Tools.VSWhere.Legacy...
Importing namespace Cake.Common.Tools.VSWhere.Product...
Importing namespace Cake.Common.Tools.WiX...
Importing namespace Cake.Common.Tools.WiX.Heat...
Importing namespace Cake.Common.Tools.XBuild...
Importing namespace Cake.Common.Tools.XUnit...
Importing namespace Cake.Common.Xml...
Importing namespace Cake.Core...
Importing namespace Cake.Core.Diagnostics...
Importing namespace Cake.Core.IO...
Importing namespace Cake.Core.Scripting...
Importing namespace System...
Importing namespace System.Collections.Generic...
Importing namespace System.IO...
Importing namespace System.Linq...
Importing namespace System.Text...
Importing namespace System.Threading.Tasks...
Error: System.ArgumentNullException: Value cannot be null.
Parameter name: imports[0]
   at Microsoft.CodeAnalysis.Scripting.ParameterValidationHelpers.AddRangeChecked[T](ArrayBuilder`1 builder, IEnumerable`1 items, String parameterName)
   at Microsoft.CodeAnalysis.Scripting.ParameterValidationHelpers.ConcatChecked[T](ImmutableArray`1 existing, IEnumerable`1 items, String parameterName)
   at Microsoft.CodeAnalysis.Scripting.ScriptOptions.AddImports(IEnumerable`1 imports)
   at Cake.Scripting.Roslyn.RoslynScriptSession.Execute(Script script)
   at Cake.Core.Scripting.ScriptRunner.Run(IScriptHost host, FilePath scriptPath, IDictionary`2 arguments)
   at Cake.Commands.BuildCommand.Execute(CakeOptions options)
   at Cake.CakeApplication.Run(CakeOptions options)
   at Cake.Program.Main()

[patriksvensson]

@Sebazzz Good catch! Thanks for reporting this.

@cake-build/cake-team I've added this to 0.23.0. Ok with you?

[devlead]

Yip 0.23.0 will be great 👍